Optical Fiber In-line Polarizer & its Fine Features

The significance and value of Optical fibers don’t need any explanations or specifications in the world of electronics and technology. These devices are no doubt the tiny part but are equally important as well as requisite for the effective / efficient working of the machinery and electronic. When we talk about optical fiber In-line polarizer these are the cogs which can never be overlooked.

Optical Fiber In-line Polarizer

Low cost optical fiber In-line polarizer is the device to convert unpolarized light into linearly polarized light. It encompasses both, input as well as output as one input of single mode fiber and one output with polarization maintaining fiber. It can easily be connected conveniently into the optical systems through pigtailed input / output connectors.

Now let’s discuss the fine features of In-line Polarizer:

• Low insertion loss: in telecommunications, the loss of signal power coming from the insertion of a device into the optical fiber is generally referred to as insertion cost. The insertion cost of the In-line polarization is stumpy and quite lesser than the other similar devices.
• High extinction ratio: the polarizer especially, the In-line polarizer usually have the high extinction ratio i.e. the ratio of the two optical power levels of a digital signal produced by an ocular source.
• High return loss: The optical fiber polarizer generates high return loss i.e. the loss of power in the signal reflected / returned by a discontinuity in a broadcast line or ocular fiber.
• Compactness and light weight: Yet another beneficial feature of an In-line Polarizer is that it is quite compact as well as light weighted. This helps in the placement and execution of the appliance. Its light weight helps it work easily and effortlessly.
• High stability and reliability: In-line polarizer is always recommended as it is quite stable as well as reliable. Unlike all other types of polarizers, the in-line polarizer has higher stability. This is the reason why companies and industries trust these.

Beyond all, the optical fiber In-line polarizer is available in market at low costs. There are several organizations which offer and sell the high quality optical fiber solutions at competitive prices and ensure you an effective as well as a durable working.

So, whenever you seek the high quality optical fiber In-line Polarizer, or decide to buy them, make sure you choose a copper-bottomed company to get the best products and high quality services as well as high class solutions at competitive prices!

DK Photonics – www.dkphotonics.com  Service to the factories, equipment manufacturers, operators and institutes who work for optical passive components, fiber communication, fiber sensing and high power laser applications, such as 1064nm High Power Isolator,1064nm High Power Circulator, Multimode Pump Combiner, Pump and Signal Combiner, Pump and PM Signal Combiner, Cladding Power Stripper, Polarization  Maintaining Optical Circulator, Polarization Maintaining Optical Isolator, Polarization Beam Combiner/Splitter, PM Filter WDM, Polarization Maintaining Filter Coupler, Polarization Maintaining Tap  Coupler, Polarization Maintaining Fused Coupler, Polarization Maintaining Fused WDM, In-line Polarizer.

10-Year Forecast – Fiber Optic Sensors

According to ElectroniCast, the combined use of Distributed and Point fiber optics sensors are forecast to reach $5.98 Billion in 2026…

 ElectroniCast Consultants, a leading market/technology forecast consultancy, today announced the release of their market forecast and analysis of the global consumption of Fiber Optic Sensors.

According to the study, the combined use of Distributed and Point (local) fiber optics sensors reached $3.38 Billion last year (2016), and the worldwide value is forecast to reach $5.98 Billion in 10-years (2026). Market forecast data in this study report refers to consumption (use) for a particular calendar year; therefore, this data is not cumulative data.

Both the American region and the EMEA region held similar market share in the overall (distributed- and point-types) fiber optic sensor value last year. The Europe, Middle East, Africa region (EMEA) held a very slight lead in relative market (value) share last year; however, the Asia Pacific region (APAC) is projected to take-over the leadership position during the forecast period.

The EMEA region is forecast to have a strong role in the use of distributed fiber optic systems, driven by the region’s use of systems in aviation, as well as in the

Petrochemical, Natural Resources, Energy/Utility application categories.

In terms of fiber optic point sensors, the American region is forecast to maintain the market share lead throughout the 1st-half of the forecast period (2016-2021), mostly led by the use of Fiber Optic Gyros (FOGs) in the Military/Aerospace application category. The consumption values are based on the end-user application and the end-user region.

FOGs held a 65 percent market share of the worldwide Point fiber optic sensor consumption value in 2016. “All regions, thanks mainly to increases in the use in aviation and military critical mission applications (Unmanned Aerial Vehicle/UAV and missile guidance, navigation, north finding/tracking, robotics, aviation and aeronautics and other) are forecast to show impressive increase consumption quantity (volumes) and values for the FOG systems,” said Stephen Montgomery, Director of the Fiber Optics Components group at ElectroniCast Consultants.

The market forecast of the Distributed Sensors is segmented by the following applications:

• Manufacturing Process/Factory
• Civil Engineering/Construction (buildings, bridges, tunnels, etc)
• Military/Aerospace/Security
• Petrochemical/Energy/Utilities/Natural Resources
• Biomedical/Science

The Fiber Optic Point Sensor Forecast further segmented by the following sensing/measuring quantity (measurand) types:

• Mechanical Strain
• Temperature
• Pressure
• Chemical, Gas, Liquid
• Vibration, Acoustic, Seismic
• Displacement, Acceleration, Proximity
• Electric, Current and Magnetic Field - Fiber Optic Sensors
• Rotation (such as Fiber Optic Gyroscopes: FOGs)

“ElectroniCast counts each Point fiber optic sensor as one unit; however, the volume/quantity (number of units) of Distributed fiber optic sensors is based on a complete optical fiber line/link, which we classify as a system. Since a distributed optical fiber line (system) may have 100s of sensing elements in a continuous-line, it is important to note that we count all of those sensing elements in a distributed system as one (system) unit – only. Distributed fiber optic sensor systems involve the optic fiber with the sensors embedded with the fiber; also included is the optoelectronic transmitter/receiver, connectors, optical fiber, cable (fiber jacket) the sensor elements, and other related components,” Montgomery added.

According to ElectroniCast, the combined use of Distributed and Point fiber optics sensors reached $3.38 Billion in 2016…

Continuous Distributed and Point Fiber Optic Sensor

Global Consumption ($3.38 Billion in 2016)

Source: ElectroniCast Consultants

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DK Photonics – www.dkphotonics.com  specializes in designing and manufacturing of high quality optical passive components mainly for telecommunication, fiber sensor and fiber laser applications,such as 1064nm High Power Isolator,1064nm Components, PM Components, (2+1)x1 Pump Combiner,Pump Laser Protector,Mini-size CWDM,100GHz DWDM,Optical Circulator,PM Circulator,PM Isolator,Fused Coupler,Mini Size Fused WDM.

Understanding the Use of Optical Fused Coupler, MUX & DEMUX WDM

In today’s high tech world, there is a desperate need for bandwidth.  The development of WDM (wavelength division multiplexing) technology has greatly helped us to expand the network capacity over a single fiber. A fiber optic coupler is a device used in fiber optic systems with input fibers (single or more) and output fibers (single or more). It is different from WDM devices.

The main benefits of Optical fused couplers are as follows:-

• Combining: This Fiber Optic Couplers combine two signals and yield single output.
• Splitting: The Splitters supply two outputs by using the single optical signal.

On the other hand, WDM multiplexer and demultiplexer divide the different wavelength fiber light into different channels. WDM is further divided into CWDM (coarse wavelength division multiplexing) and DWDM (dense wavelength division multiplexing). Generally, the WDM systems operate on 9µm single-mode fiber optical cables although it is not necessary.

If we specifically talk about the CWDM method, CWDM multiplexes multiple optical carrier signals on a single optical fiber. It uses different wavelengths/colors of laser light combined in a MUX in order to carry different signals. Mux/DeMux is one of the most important components of CWDM systems.

The LGX CWDM Mux and DeMux module comes with a 8 Channel (dual fiber) with 1U 19 Rack Mount Box that utilizes thin film coating technology and proprietary design of non-flux metal bonding micro optics packaging. It has been designed to provide optical networking support over a grid of CWDM optical wavelengths in high-speed Fibre Channel and Ethernet communication for metropolitan area networks (MAN).

The optical component is easy to operate with a reliable low-maintenance design. The MUX is passive and it does not use power supplies or electronics. It is capable of multiplexing and demultiplexing ITU-T G.694.2 wavelengths up to 8 channels in increments of 20nm from 1270 nm to 1610 nm. “ITU” specifies the exact center of 8CH CWDM Mux and Demux dual fiber 1U 19 Rack Mount Box wavelength such as 1531nm, 1591nm, 1611nm, etc.

The 8 Channel CWDM Mux and Demux dual fiber 1U 19 Rack Mount Box are protocol and rate transparent. They allow different services up to 10Gbps transported across the same fiber link. It works seamlessly with transceivers to optimize the link length, signal integrity, and overall network cost. It can be incorporated into a single rack-mount solution for a better design, power, and space efficiency.

As per the working principle, MUX and DEMUX can be used in various fields, such as communication systems, computer memories, telephone networks, etc. It is a cost saving method of connecting a multiplexer and a demultiplexer together over a single channel.

How to get the Optical Fused Couplers, Mux and DeMux WDM?

There are several leading companies in market that are considered masters at the designing and manufacturing of optical passive components for fiber laser, fiber sensor, and fiber optic telecommunication applications. One can contact these companies to avail high quality opticalcouplers, Mux and DeMux at affordable rates.

Contact a supplier today and get them.

WDM And The Modules Based On It: The Need Of The Hour

In fiber-optic world of communication, wavelength-division multiplexing or WDM is an innovation which multiplexes various optical transporter signals onto a solitary optical fiber by utilizing distinctive wavelengths, that is the shades of the laser light. This system empowers bidirectional interchanges in more than one strand of fiber, and also increases the limits and domains of it. The term wavelength-division multiplexing is generally connected to an optical transporter, which is normally depicted by its wavelength, though recurrence division multiplexing is commonly applied to a radio bearer which is all the more of a frequently portrayer by recurrence. This is a simple convention since wavelength and recurrence convey a similar data.

How a WDM system works:

A WDM framework utilizes a multiplexer at the transmitter to combine the few signs and a demultiplexer at the collector to part them separated. Hence, WDM Mux and DeMux Modules are made to be used with the correct kind of fiber as it is conceivable to have a gadget that does both all the while, and can work as an optical add-drop multiplexer. The optical filtering gadgets utilized have ordinarily been etalons or to say, stable solid-state single-frequency Fabry–Pérot interferometers in the form of a thin-film-covered optical glass.

Need of WDM Multiplexing:

Since the physical fiber optic cabling is costly to actualize for every single company independently, its ability development by utilizing a Wave Division Multiplexing (WDM) is the need of the hour. WDM innovation was created to extend limits of single fiber systems can give. A WDM framework utilizes a Multiplexer at the transmitter to join a few wavelengths together; thus each one conveys diverse flag and signals via a demultiplexer at the recipient to make them separated. Both Mux and Demux are latent parts of the circuit, as their requirement of power is nil.

Types of WDM available:

These days there are a few sorts of institutionalized WDM in availibility:

• General WDM, for example, 980/1550 WDM, 1310/1550 WDM.
• CWDM incorporates CWDM mux/demux module and CWDM OADM module. The normal setup of CWDM mux/demux module is 2CH, 4CH, 8CH, 16CH, 18CH CWDM mux/demux module. Single fiber or double fiber association for CWDM Mux/demux are accessible.
• DWDM incorporates 50GHz, 100GHz, 200GHz DWDM mux/demux module and DWDM OADM module. The normal arrangement is 2CH, 4CH, 8CH, 16 CH, 32CH, 40CH channels.
• They are accessible as Plastic ABS module tape, 19'' rack mountable box or standard LGX box. What's more, regardless of what sort of connectors, as FC, ST, SC, LC and so on, all is available on DK Photonics, and they additionally can blend connector on one gadget. DK Photonics Technology Limited is one of the main organizations in outlining and assembling of fantastic optical inactive parts primarily for media transmission, fiber sensor and fiber laser applications. Headquarter and manufacturing plant is situated in Shenzhen of China. Savvy, best quality and best administration are forever their objective. So if you have any requirement regarding the WDM or any of the devises based on it, DK Photonics is the reliable and trusted brand!

Two Types Of Polarization Beam Combiners & Splitters

Polarizing Beam combiners / splitters are the devices used to combine two polarized light signals or split single non-polarized light into two polarized parts. These combiners and splitters are designed and developed to split light beams by deploying the polarization state and not by wavelength or intensity.

The polarizing beam splitters / combiners typically have 0° or 45° angle of incidence and a 90° division between the beams; this generally depends on the configuration. There are two types of Polarization beam combiners and splitters; these are described below:

1. Incoherent Polarization Combining / Splitting

The Incoherent combining or splitting is the simpler variant and the basic technique. In this method, the resulted beams of two broad area laser diodes are sent onto a thin-film polarizer so as to reflect one of the beams while transmit the other; both of these beams then propagate in the same direction. As a result, one attains an unpolarized beam (with the combined optical power of the input beams) and the same beam quality. Consequently, the brightness gets nearly doubled.

This technique is often used for any-a-applications, for instance, end-pumping of a solid state laser with an increased power. However, the technique is not suitable for power scaling.

1. Coherent Polarization Combining / Splitting

With coherent beam combining or splitting it is viable to attain a linear polarized state in the output, if two mutually coherent beams are combined. If two ports have the equal input powers, the output polarization would be typically rotated by 45° -depending on the polarization direction of any of the input beams.

Also, the coherent polarization combining can be repeated several times because of the linear output polarization. Thereby, this technique is suitable for power scaling.

A polarization beam combiner and splitter is often used in photonics instrumentation, optics and semiconductors to transmit p-polarized light while reflecting s-polarized light. These hold a world of worth when it comes to optics, telecommunication and fiber applications, and make the working effective as well as effortless.

Learning the Different Coating Stripping Methods

The cladding power stripper also referred to as the multimode optical power stripper is designed for amplifier applications and high power fiber laser. It is an ideal device  for ASE, residual pump power stripping, core modes that have escaped from double cladding fibers inner cladding while ensuring preservation of single power minimal degradation and beam quality (M2). Single power that is reflected into the inner cladding may also be stripped out too.  The handling capability of the stripping power goes to 800W or at times may be even higher

Stripping the Coating

The fibers that most reputable companies supply all come with a standard  acrylate single layer coating or, in some such as the high power products, a coating that is high temperature enduring. In comparison to dual layer coatings, the coatings that are single layer are more brittle and smooth. The coating can be removed readily using the conventional tools for fiber stripping such as the Fitel S-210 Clauss or CFS-1 for 125 μm cladding diameter fiber or for larger cladding diameters the Clauss No Nik stripper is used. For fibers whose outer diameter is non-standard, it is recommended that an adjustable stripper is used.  Thermal strippers such as those that are attached to the Schleuniger FiberStrip 7030 or the Vytran FFS-2000 can be used for all fiber in a safe way.

Alternatively, chemical stripping of fibers can be done using an appropriate solvent. For example, the coating can be exposed for one minute to sulfuric acid at 120°C sulfuric acid. Before the fiber is dipped into the liquid, the tip should be sealed with a drop of glue of 2 mm in diameter or through the end fiber hole collapsing using a fusion splicer.  It is worth noting that most glue types are dissolved in this acid, but epoxies that are two-component such as the Epotek ND353 tends to dissolve in a slower manner than the coating.

It is also possible to obtain chemical stripping through application on the fiber tip, of paint stripper. The paint stripper is usually in the form of a gel so as to reduce the occurrence of out-gassing and can be applied easily using a small brush. After a minute or so, the coating becomes soft and is removed easily using a lens tissue. It is worth noting that paint stripper typically contains dichloromethane (CH2Cl2) and as such there may be restrictions by local regulations to use it. For lower quality and faster stripping, another option would be to use a normal cigarette lighter to burn the coating off. However, the fiber may end up becoming brittle hence not the best choice for stripping.

Pump and signal combiner for bi-directional pumping of all-fiber lasers and amplifiers(10)

7. Signal feedthrough of the fiber combiner

Besides the pump power handling and the pump coupling efficiency of a fiber combiner, it is important for fiber laser and amplifier applications to maintain the optical properties of the signal light propagating through the fiber combiner. In particular, during the fabrication of the fiber component, externally induced mechanical stress and perhaps a marginal fraction of thermal diffusion of the core dopants [19] can result in a high signal insertion loss in conjunction with a degradation of the signal beam quality. This behavior was expected for large mode area DC fibers with a very low core refractive index (NA ~0.06), and therefore possible beam quality degradations of the signal feedthrough light was investigated (in Section 7.1).

The uninterrupted signal core in the fiber combiner provides the possibility of passing a signal beam through the combiner in forward and backward direction. However, in the case of a backward propagating signal, the pump diodes need sufficient protection against the signal. Thus, in Section 7.2 we investigate the signal to pump isolation of a 4 + 1x1 fiber combiner in a fiber amplifier setup.

7.1 Signal insertion loss and beam quality

In order to determine possible beam quality degradation and a signal insertion loss caused by the signal feedthrough of the combiner, the setup depicted in Fig. 14

Fig. 14 Setup for beam quality measurements, TF: target fiber, PBS: polarization beam splitter.was used. A signal at a wavelength of 1064 nm was launched into the core of a 2.75 m long Ytterbium-doped DC fiber (Nufern YDF-25/250), which is specified with a signal core diameter of 25 µm (NA 0.06) and a pump core diameter of 250 µm (NA 0.46). Thus, the parameters of the passive TF of the combiner were matched to the active fiber. The coiling diameter of the active fiber was 12 cm to maintain near diffraction limited beam quality [20]. The transmitted signal had a power of about 200 mW and was propagating in reverse direction through the fiber combiner. The beam quality measurements were carried out with a Fabry-Perot ring-cavity. With this cavity it was possible to determine the power fraction in higher-order transversal cavity modes with respect to the Gaussian TEM00 mode by scanning the length of the ring-cavity over a free spectral range (FSR). A detailed description of the measuring setup can be found in Ref [21]. Due to the use of a polarization sensitive beam quality measurement, a half- and a quarter-wave retardation plate in conjunction with a polarization beam splitter (PBS) were used. The determined polarization extinction ratio was better than 17 dB after the propagation of the signal through the active fiber and the fiber combiner.

Before the fusion splice between the active fiber and the 4 + 1x1 combiner, the power in higher-order modes of the active fiber was determined. This measurement served as a reference beam quality for the active fiber. The mode scan in Fig. 15(a)

Fig. 15 Normalized transmitted intensity through a premode cleaner as a function of the ring-cavity length in units of a free spectral range for (a) the reference beam and (b) the signal feedthrough beam of a 4 + 1x1 fiber combiner.

shows the logarithmic normalized intensity over a free spectral range for the reference beam with a power in higher-order modes of 3.1%. This results in a fundamental fiber mode power of at least 96.9% for the reference beam. For the signal feedthrough of the fiber combiner, a power in higher-order modes of only 5.1% was found (Fig. 15(b)).

Consequently, the signal feedthrough fiber (0.7 m long TF) only led to an increase in power in higher-order transversal modes of maximal 2%. Furthermore, it must be considered that additional power transfer to higher-order transversal modes can also be caused by the fusion splice between the active DC fiber and the TF. Hence, good preservation of the signal beam quality, in conjunction with the low signal insertion loss of less than 3%, provides an excellent high power fiber component for monolithic fiber laser and amplifier systems.

Work Theory of the Laser Cutting Machine(2)

Cutting methods of laser cutting machine

Vaporization cutting

It means that vaporization is the main way to remove the processed material. In the process of vaporization cutting, workpiece surface is heated to vaporization temperature quickly by focused laser beams, forming High pressure steam and spraying outward at supersonic speeds. In the meantime, a hole is formed in the laser active area and laser beams reflex several times in the hole to increase the absorption of laser pump power combiner by material.

When high-pressure vapors spray outward, the melted materials are blown away in the kerf till the workpiece is finally cut. Vaporization cutting needs very high power density, which is eighth power of ten watt above per square centimeter. It is usually applied in low flash point materials and refractory materials.

Reaction Fusion Cutting

When assistant airflow not only blows the melted materials from the kerf but also has thermal reaction with the workpiece, this is the so-called reaction fusion cutting. Gases that can have reaction with workpiece are oxygen or mixture gases containing oxygen. When the surface  temperature of workpiece reach to ignition temperature, strong combustion heat release occurs to improve the laser cutting ability.

Combustion heat release of low carbon steel and stainless steel is 60%. And it is about 90% for reactive metals like titanium.

Compared to vaporization cutting and general fusion cutting, reaction fusion cutting need less laser power density. However, reaction fusion cutting may effect the performance of worpiece since the combustion reaction can lead to chemical reaction on materials.

Fusion Cutting

When adding a assistant airflow system coaxial with laser to  blow the melted materials away from kerf, this kind of cutting is fusion cutting. In fusion fiber coupler cutting, workpiece needn't to be heated to vaporization temperature so the required laser power density is reduced greatly.

Laser Scribing

It is mainly used in semiconductor materials, in which laser of high power density make a shallow groove in the semiconductor materials of the workpiece and then makes it crack through mechanistic or vibratory methods. The quality is valued by the surface fragments and size of heat affect area.

Cold Chipping

It is a new processing method, which is put forward along with ultraviolet band superpower excimer laser appeared in recent years. The basic theory is that energy of ultraviolet photons is similar to binding energy of many organic materials; this high-energy photons are used to impact bond organic materials thus make it crack, achieving purpose of cutting. This new technology has promising application future, especially in electron industry.

Thermal Stress Cutting

Mechanism of thermal stress cutting is that laser beams heat an area of fragile material to produce evident temperature gradient. The high surface temperature makes expansion and inner lower temperature hinders expansion, forming pulling stress in the surface and radial crushing stress inside. When the two stresses exceed fracture limit strength of the workpiece, crackle appears. And then the workpiece is broken along the normal direction of the crack. It is suitable for glasses and ceramics.

Conclusion: laser cutting machine is a cutting technology of melting and gasifying surface material through focused energy generated by the use of laser specialties and focused lens. It features good cutting quality, high speed, various cutting material and high efficiency.

About DK Photonics

DK Photonics – www.dkphotonics.com  specializes in designing and manufacturing of high quality optical passive components mainly for fiber laser applications such as 1064nm high power isolator, Cladding Power Stripper, Multimode High Power Isolator, pump combiner,1064nm Band-pass Filter,(6+1)X1 Pump and Signal Combiner, PM Circulator, PM Isolator, optical Coupler. More information, please contact us.

Work Theory of the Laser Cutting Machine(1)

Laser has been applied in teaching, military as well as industrial production. Laser cutting machine is one of the applications. It can be used in both metal and non-metal cutting, Melting surface material by laser beam. This article will discuss the work theory of laser cutting machine.

Introduction on the work theory of laser cutting machine.

Laser cutting machine adopts the energy released on the time when laser beam irradiate metal surface. The metal is melt by laser and sinter is blow away by gas. Because laser power is highly focused, only a very little heat effects the other part of metal plate and causes a little or no deformation. Laser can cut any complex shape precisely, which needs no further processing.

Laser source is generally CO2 laser beam high power isolator with operating power of 500～5000W. The power is even lower than that of many household electric heater, and because of lenses and reflectors, laser beams are focused in a very small bit of area. Highly focused energy heat the area quickly and makes the metal plate melted.

Laser cutting machine can cut stainless steal of thickness less than 16mm; when adding oxygen in laser beam, the cutting thickness is 8～10mm but it will generate a thin oxidation film in the cut surface. The maximum thickness is 16mm which leads to larger cutting deviation on the size of components.

Since the advent of laser, numerous laser products have been developed, such as laser printer, laser cosmetic instrument, laser marker, laser cutting machine etc. Due to its late start in China, the laser technology in China is greatly behind the developed countries. Although Chinese manufacturers can produce plenty of laser products, some key parts such as laser tube, driving motor, galvanometer and focus lens are imported products. This leads to an increase on cost thus an increase on consumer's payment.

In recent years, domestic research and production of  laser products become closer to advanced overseas products with the progress of laser technology in China. Some aspects are even superior to products abroad, which has a leading role in market because of the  advantages of price. Overseas products have absolute predominance in precision machining for its quality on stability and endurance.

Work theory of laser cutting machine

Laser tube is the core part of laser cutting machine. So, below is an introduction of the most popular laser tube. CO2 laser tube.

Laser tube is composed of hard glasses, so it is fragile. It adopts layer of sleeve construction with discharge tube in the most inside layer. However, the diameter of discharge tube is thicker than laser tube, diffraction between the thickness of discharge tube and the size of flare is in direct ratio; the length of tube is in proportion to output power of discharge tube.  Laser tube generates a large quantity of heat in the operation of laser cutting machine, which influences the normal work. So cold water machine is needed to cool laser tube, ensuring constant temperature for successful running.

Cutting features of laser cutting machine

Advantages of laser cutting:

One — high efficiency

Laser cutting machine is always connected to several numerically-controlled rotary tables to achieve numerical controlled cutting. It only needs to change the NC program to adjust to components of different shapes, which can make 2D cutting as well as 3D cutting.

Two — high speed

When cutting low carbon steel sheets of 2mm thickness, the speed of 1200W laser cutting is 600cmmin; when it is 5mm thick polypropylene resin plate, the cutting speed is 1200cmmin. The material needs no clamping fix in laser cutting process.

Three — high quality cutting

Laser cutting features thin kerf. The two sides of kerf are parallel and the kerf is vertical to the surface. The cutting precision can reach to ±0.05mm. The cutting surface is clean and nice, with roughness of tens of microns. The cut components can even come into use directly without further machining. After laser cutting, the heat effected area is very small and material near to kerf has not been affected, making little deformation, high cutting precicion and perfect geometrical shape

Four — non-contact cutting

Laser cutting is non-contact cutting, which means no tool wear problem. When processing different shapes, there is no need to change tools, the only way is to alter the output parameter of laser. The whole laser cutting process features low noise, little vibration and little pollution.

Five — various cutting material

Compared to oxyacetylene cutting and plasma cutting, laser cutting can be applied on more materials, including metal and non-metal, metal matrix and non-metallic matrix composite, leather, wood as well as fibers.

About DK Photonics

DK Photonics – www.dkphotonics.com  specializes in designing and manufacturing of high quality optical passive components mainly for fiber laser applications such as 1064nm high power isolator, Cladding Power Stripper, Multimode High Power Isolator, pump signal combiner,1064nm Band-pass Filter,(6+1)X1 Pump and Signal Combiner, PM Circulator, PM Isolator, optical Coupler. More information, please contact us.

Pump and signal combiner for bi-directional pumping of all-fiber lasers and amplifiers(9)

6. Demonstration of 440 W pump power handling

After detailed theoretical and experimental characterization of fiber pump combiners with multiple pump ports, a pump power handling performance test was conducted. For these investigations each pump port of a 4 + 1x1 combiner was connected to a fiber coupled pump diode (nLight Pearl) with an output power of ~110 W at a wavelength of 976 nm. The PFF and the delivery fiber of the pump diode had a core diameter of 105 µm with a NA of 0.22. At each fiber output end of the IF, a pump light stripper was applied to avoid the Fresnel reflection of the TP, and therefore the TP was not measured. Up to the maximum total pump diode power of 440 W, a coupling efficiency of 90.2% was experimentally determined (Fig. 13

Fig. 13 Combined pump power for a 4+1x1 high power fiber combiner, * ratio of coupled power to total diode power in percent.

). In the simulations a slightly higher coupling efficiency of 92.8% was obtained. The difference of 2.6% in simulated and measured pump light coupling must be distributed among TP, PAA and PCT, with simulated values of 3.0, 1.4 and 1.7%, respectively. It can be assumed that the PAA-fraction is higher than 1.4%, since the fibers of the combiner are contaminated with dust particles in spite of intensive cleaning. If we assume for each individual loss mechanism an error of 1% related to the total diode power then PCT was 7.5 W ± 4.4 W, i.e. the coating of the TF and the pump power stripper had to handle this fraction of power.

About DK Photonics

DK Photonics – www.dkphotonics.com  specializes in designing and manufacturing of high qualityoptical passive components mainly for fiber laser applications such as 1064nm high power isolator,Cladding Power Stripper, High Power Isolator,pump combiner,1064nm Band-pass Filter,(6+1)X1 Pump and Signal Combiner,PM Circulator,PM Isolator,optical Coupler.More information,please contact us.

Fiber Laser Welding: Some Traits and Applications(2)

Technological parameter of laser welding:

(1) Power density

Power density is one of the key parameters in laser processing. When the power density is relatively high, the surface would be heated to boiling point in microseconds, thus generate mass vaporization. As a result, high power density is good for material removal processing such as punching, cutting and carving. When the power density is relatively low, it would take some microseconds to meet the boiling point, the bottom can reach the melting point before vaporization occurs, thus a good melt welding is successfully formed. So the power density ranges from 104~106W/cm2 in conductive laser welding.

(2) Laser pulse shape

Laser pulse shape is an important question in laser welding, especially for foil welding. When high strength laser beam reaches the material surface, 60~98% of the laser energy will be lost by reflection and the reflectivity is changeable by the temperature of the material surface. The reflectivity of metal can vary greatly in a laser pulse period.

(3) Laser pulse width

Laser pulse width is an important parameter to distinguish material removal and material melting; it is also a key parameter to decide the cost and volume of processing equipment.

(4) Influence of defocusing amount on weld quality

There are two ways of defocus: positive defocus and negative defocus. It is positive defocus when focal plane is above the workpieces, vise versa. According to geometry optical theory, when positive and negative defocusing plane equals to welding plane, the power densities are almost the same in the corresponding panels, but the actual laser pools have different forms. It can achieve larger depth of fusion when it is negative defocus.

Application field of laser welding

Laser welding machine has wide application in manufacturing industry, powder metallurgy field, automobile industry, electronics and some other fields.

Source : demarlaser

Application of laser welding in automobile industry

Volkswagen AG has adopted laser welding in car roof of brands like AudiA6, GolfA4 and Passat. BMW and GM have used laser welding in top of the car frame while Mercedes-Benz has applied laser welding in drive disk assembly. Except for laser welding, other laser technologies have be applied as well. Companies like Volkswagen GM, Benz and Nissan have used laser to cut covering parts while FIAT and Toyota have adopted laser for coating engine exhaust valve; Volkswagen has used laser for surface hardening on engine camshaft. Domestic vehicle models like Passat, Polo, Touran, Audi, Dongfeng Peugeot and Focus have adopted laser welding technology.

Independent automobile brands like Brilliance, Chery and Geely have adopted laser welding as well.

Improvement and development of new laser welding technology

Laser welding technology is continuously developing along with the progress of the time. The following three technologies can help expanding laser's application scop and enhancing the automatic control level of laser welding.

1. filler wire laser welding

Laser welding generally doesn't fill wires but has high requirement on assembling clearance, which is hard to be guaranteed thus limits the application scope. Filler wire laser welding method has lower requirement on assembling clearance. For example, if the aluminum alloy plate is of 2 mm's thickness, the clearance must be zero for a good shaping. When adopting φ1.6mm welding wire as filler metal, it can form good shape even the clearance is 1.0 mm. Besides, filler wire can be used for adjusting chemical components and multi-layer welding on thick board.

1. Beam rotation laser welding

By the adoption of laser beam rotation laser welding methods, demands on welding assembly and beam centering are reduced greatly.

1. On-line detection and control of laser welding quality

It is becoming a hot researching topic on detecting laser welding process by using plasma such as light, sound and electric charge; some researches have achieved closed-loop control.

DK Photonics – www.dkphotonics.com  specializes in designing and manufacturing of high quality optical passive components mainly for fiber laser applications such as 1064nm high power isolator, Cladding Power Stripper, Multimode High Power Isolator, pump combiner,1064nm Band-pass Filter,(6+1)X1 Pump and Signal Combiner, PM Circulator, PM Isolator, optical Coupler. More information, please contact us.

Fiber Laser Welding: Some Traits and Applications(1)

What is fiber laser? The world's first laser beam is produced in 1960 by the use of flashbulb stimulating ruby crystalline grain. Limited by the thermal capacity of the grain, the pulsed beams is short and the frequency is very low. Although the instantaneous pulse peak can reach up to 106W, it still belongs to low energy output.

Source:tamu.edu

Laser technology adopts the beams of light generated by the reflection of laser from polariscope and congregates the beams in focusing device to generate beams with enormous energy. Once the focus is approaching, the workpieces will be melt or vapored in some milliseconds. This opens up a new welding application domain for high power CO2 and high power YAG laser. The key of laser welding equipment is high power laser, including solid laser and gas laser. Solid laser is the so called Nd:YAG laser. Nd is a rare earth elements and YAG represents Yttrium Aluminum Garnet, with similar crystal structure as ruby. The wavelength of Nd:YAG laser is 1.06μm. It can produce beam transmitted by fiber, so it can simplify beam delivery system, which is suitable in flexible manufacturing systems and remote working as well as high welding precision workpieces. Nd:YAG laser of 3-4 KW output is commonly used in automobile industry. Gas laser is the so-called CO2 laser. Its working medium is molecule gases which can generate iraser of 10.6μm in average. It can work continuously and output very high power; the standard laser power is between 2-5 KW.

The major traits of laser welding are as following:

1. The welding is fast and deep with little deformation.
2. It can work in room temperature and disparity conditions with simple equipment and device. For example, the laser beam will not offset; laser welding can be really carried out in vacuum, air or any gas environment, or even through glass or any transparent material.
3. It can weld refractory materials as titanium and quartz and anisotropic materials with good effects.
4. When welding, depth-to-width ratio can reach to 5:1 and the highest can reach up to 10:1.
5. It can applied in microwelding. Slight flare can be generated by focused laser beams which can positioning precisely and be applied in mass automatic production of micro and small workpieces' installation and welding.
6. It is flexible in welding areas that is difficult to access. Especially in recent years, the adoption of optical fiber transmission in YAG laser processing technology has greatly promoted the popularization and application of laser welding technology.
7. Beam split is easy to be realized by time and space and multiple beam can be processed all at once, providing conditions for more precise welding.

However, there are some limits of laser welding:

1. It requires high assembly accuracy for weld and it should has no obvious deviation of beam on workpieces. It is because that the flare is too small and the welding line is too narrow. If the assembly accuracy and beam position cannot meet the requirements, it is easy to make weld defect.
2. The cost and initial investment on laser and the relevant systems are high.

Resource : avio

DK Photonics – www.dkphotonics.com  specializes in designing and manufacturing of high quality optical passive components mainly for fiber laser applications such as 1064nm high power isolator, Cladding Power Stripper, Multimode High Power Isolator, pump combiner,1064nm Band-pass Filter,(6+1)X1 Pump and Signal Combiner, PM Circulator, PM Isolator, optical Coupler. More information, please contact us.

The Comparative Between Fiber Laser Cutting Machine and CO2 Cutting Machine

Cutting is one of the most widely applied laser processing techniques. Fiber laser and CO2 laser are the most commonly used laser cutting equipment. It is necessary for users to have a knowledge of the advantages and disadvantages of both the two ways of cutting.

Source : fe.infn

Wavelength of fiber laser is 1.06μm and Wavelength of CO2 laser is 10.6μm. Both are infrared light and can be absorbed by material so that they can be applied in Industrial material processing. Fiber laser is unable to be applied in non-metal cutting, such as wood, plastic, leather and ramie cotton fabric. In case of non-metal cutting, CO2 laser is the only choice. But CO2 laser cannot cut copper products, including brass and red copper. Because copper is highly reflective material for CO2 laser, laser will be reflected instead of absorbed by copper, which can cause harm.

Laser is evaluated by integrated index as cutting speed, drilling efficiency and section quality.

Fiber laser has an advantage in cutting thin plate, especially for thickness under 3mm. Its maximum cutting speed ratio can reach to 4:1 and 6mm is critical thickness for the two kinds of lasers. When it is thicker than 6mm, fiber laser shows no preferential; as the thickness increases, CO2 laser shows preferential gradually but not outstandingly. Generally speaking, fiber laser has an advantage in cutting speed.

Drilling efficiency:

Before cutting, laser beam should penetrate workpiece. Fiber laser needs more time in drilling than CO2 laser. Take 3KW optical fiber laser and CO2 laser as an example, The latter saves 1 second in drilling 8mm carbon steel; and 2 seconds in 10mm drilling. As thickness grows, CO2 laser will save more time.

Source : nufern

Section quality:

Section quality usually means the roughness (surface perfection) and perpendicularity.

When cutting steel plate under 3mm, section quality of fiber laser is worse then CO2. As thickness grows, the difference becomes more obvious.

In addition, carbon steel plate has high absorptivity on fiber laser energy, so it has shortcoming in cutting holes (aperture < panel thickness).

The above comparison will help users make a reasonable choice. The cutting speed of the two lasers is equally matched. Fiber laser is inferior to Co2 laser in section quality and drilling efficiency. There is no quick answer to which is better. They both have advantages and disadvantages in specific application demands.

By the way, laser cutting precision has nothing to do with the adoption of lasers. It is determined by machine positioning precision, resetting precision and consistency of kerf width. Fiber laser has narrower kerf than CO2. Kerf width doesn't affect precision of the parts either, since it can be offset by cutting gap compensation.

DK Photonics – www.dkphotonics.com  specializes in designing and manufacturing of high quality optical passive components mainly for fiber laser applications such as 1064nm high power isolator, Cladding Power Stripper, Multimode High Power Isolator, pump combiner,1064nm Band-pass Filter,(6+1)X1 Pump and Signal Combiner, PM Circulator, PM Isolator, optical Coupler. More information, please contact us.

Field-Terminated Fusion Splice-On Connector-North American Market Forecast

According to ElectroniCast, the quantity of field-terminated fiber optic splice-on connectors in North America will increase at an explosive annual rate of 41.9% …

ElectroniCast Consultants, a leading market research & technology forecast consultancy addressing the fiber optics communications industry, today announced the release of a new market forecast of the consumption of field terminated fiber optic fusion splice-on connectors in North America.

Field terminated fiber optic fusion Splice On Connectors (SOC) are installed for rapid repairs or for limited space situations where pre-terminated fiber cabling may be difficult, such as when the cable assembly needs to pass through small openings such as conduit.  The splice-on connectors are an option when the precise length of the optical fiber link is not pre-determined and a field-installed termination solution is required, such as in Fiber to the Home (FTTH) and other communication applications.

Last year, 306-thousand field-terminated fiber optic fusion splice-on connectors were installed in non-OEM applications in North America.  The number of connectors is forecast to increase at an explosive rate of 41.9% per year, reaching 2.49 million units in 2020.  Market forecast data in this study report refers to consumption (use) for a particular calendar year; therefore, this data is not cumulative data.

The Telecommunications application category is forecast to maintain the leadership in relative market share through the year 2018, until the Premises Networks application category is set to capture the lead.  Telecommunication use is forecast for 35.5% annual growth in quantity (2014-2020), mainly driven by access optical fiber deployment.  The Cable TV application is also driven by the use of connectors for FTTH (Home) and FTTB (Building/MDUs – Multiple Dwelling Units).

The market forecast segments the connectors by single-mode and multimode optical fiber, as well as into the following types: MPO, LC, FC, ST, SC, and other.  The use of single mode fiber optic field-terminated fusion splice-on connectors in North America is forecast to increase from 173.8-thousand units in 2014 to 1.49 million in 2020.  Multimode fiber is best suited for use in short lengths, such as those used in datacom and specialty networks and in 2020, multimode connectors are expected to reach 1-million units.

“In 2014 in North America, 4.3-thousand new fusion splicers were brought into Premises Datacom, and the use of field terminated fusion splice on connectors is a major market driver for the use of fiber optic fusion splicers used in premises network applications, the data center (DC) and longer link length datacom cable installations,” said Stephen Montgomery, Director of the ElectroniCast market study.

“The SOCs are emerging as a viable alternative to pre-terminated fiber optic cables (pigtail and cable assemblies/ patch cords).  Also, based on primary research interviews with network planners and installers, we are finding that field terminated fusion splice-on connectors are rapidly being accepted as a go-to solution.  With SOCs, communication network technicians can install reliable cable links with exact lengths, eliminating cable shortness or excess slack that is typically a result with the pre-terminated cable solution,” Montgomery added.

Tags: CWDM Multiplexer, DWDM Multiplexer,19" rack mount chassis CWDM, ABS plastic box, CWDM MUX/DEMUX Module,  LGX CWDM Module,8CH CWDM Module, 16CH CWDM Module

The Modern Data Center – Modular Data Center

The modern data center is a complex place. The proliferation of mobile devices, like tablets and smartphones, place an ever-increasing pressure on the IT departments and data centers. End-user and customers’ expectation levels have never been higher and the demand for data shows no sign of slowing down. Data center managers must manage all of these elements while also remaining efficient and keeping costs under control. So where does the data center go from here?

One thing I have noticed in the evolution of the modern data center is that the facilities are gaining importance; improving energy efficiency and IT management have come to the forefront. Maximizing the organization’s resources is vital, and that means delivering more to facilities and equipment without expending more on staffing. IDC forecasts that during the next two years, 25 percent of all large and mid-sized businesses will address the power and cooling facility mismatches in their data centers with new IT systems and put a 75 percent cap on data center space used. So there again is the crucial challenge of doing more and innovating while keeping budgets and spend under control.

Another key part of the next generation data center mix is automation. Today’s data center manager is engaged in sourcing the right automation tools that will help them manage energy consumption and add new technology without disrupting normal operations. These are a few of the key challenges in the modern data center—so data center managers and IT departments must find ways to address them.

Where does the Data Center Go Next?

At the heart of data center evolution is the information technology sector’s rapid rate of change. Many new products and services must be implemented with much less time to value, and data centers need to be agile enough to assess and accommodate them all. If you examine enterprise data centers, then you might observe the ways that cloud computing and hyperscale innovations are displacing traditional enterprise systems, with new paradigms pioneered by innovators like Amazon and Google. With new options being developed, enterprises now have to chart strategies for cloud computing, including public, private or hybrid cloud. Gauging where the technology will go next is difficult to tell. Will the traditional vendors, such as Cisco and EMC, prevail or will new paradigms from Nutanix or Simplivity disrupt and displace these traditional data center dominators?

The race is on to manage the rapid rate of change while also staying agile, meeting end-user expectations and managing costs. For example, data center managers must handle the level of capacity their data center requires while ensuring they don’t overspend on unused capacity. This is where the focus on data center design comes into play.

Taking the Data Center Forward

These specific needs and challenges that the modern data center faces require working with the right tools and solutions. Modular, purpose-built data center infrastructure allows organizations to develop data center services based on need—when capacity rises and where capacity is needed. For example, we’ve observed in Singapore that most data centers operate slightly above 2.1 Power Usage Effectiveness (PUE). This means that companies spend more on cooling their data center rather than on operating and powering the IT equipment. It is a simple challenge—drive efficiency without impacting operations. You want to drive PUE down to approximately 1.06, regardless of where you need to operate, and reap huge energy savings while better serving customers. If done right, there is a positive environmental impact.

Changing the paradigm of the traditional data center enables organizations to reap these rewards. Assessing and establishing business objectives that reflect what is possible, rather than what always has been or what is easier and more comfortable, has led to innovative services and new business models that reset the competitive standards for everyone. Better PUE is a mandatory step in this process. The PUE journey continues as evidenced by Amazon, which had recently taken to harnessing wind to power its data centers. Modular data centers will play a major part in this PUE journey, thanks to more efficient use of energy and greater flexible support for resiliency and compute density.

How much do you know about CWDM Multiplexer and DWDM Multiplexer

CWDM multiplexer and DWDM multiplexer are two main products of WDM multiplexer. The full name of WDM, CWDM and DWDM are wavelength division multiplexing, coarse wavelength division multiplexing and dense wavelength multiplexing respectively. How much do you know about them? If you have no idea, the following introduction will help you a lot.

In the very first place, let's get to know what the WDM is. Based on a single fiber optic transmission, many optical signals that are loaded with information and have different wavelengths can be synthesized into one single beam by WDM multiplexer. Then, a special communication technology will be adopted to separate those optical signals at the receiving terminal. On the basis of WDM technique, the CWDM device and DWDM device are two popular products in the current market.

CWDM device

When it comes to the CWDM multiplexer, first of all, it provides service for metropolitan area network access layer, whose working principle is in line with WDM multiplexer. However, it simplifies the structure largely. For example, the filter film layer number of CWDM is just 50, while the WDM is as many as 200 layers. That is to say, the rate of finished products has been improved and the cost has been reduced largely. Besides low cost, the CWDM device is also advantageous in small volume, small power consumption, convenient maintenance and large transmission capacity. The laser device in the system doesn't need semiconductor refrigerator and temperature controller, which can lessen the power consumption obviously. However, the CWDM also has shortcomings. For instance, developing and simplifying the optical transceiver module and optical component is urgent to be solved.

DWDM device

As to the DWDM multiplexer, comparatively speaking, it makes the best use of fiber-optical bandwidth and enhances the message capacity of cellular system, which is well-known for simple dilatation and stable performance. Integrated system and open system are two dominant application systems of DWDM multiplexer, which are based on different wavelength conversion technologies. No matter which system is adopted, the free-running 1510nm wavelength will be chosen to carry OSC or optical supervisory channel so as to transmit information. Such an OSC is a comparatively independent subsystem, which offers maintenance and management information.

The last question is what advantages WDM technique has when compared with traditional transmission methods. Generally speaking, it includes such aspects as making best use of low-loss wave band, transmitting several optical signals in one optical fiber, good flexibility, low investment cost, excellent system reliability and fast and convenient recovery.

Tags: CWDM Multiplexer, DWDM Multiplexer,19" rack mount chassis CWDM, ABS plastic box, CWDM MUX/DEMUX Module,  LGX CWDM Module,8CH CWDM Module, 16CH CWDM Module

Do you know these about CWDM Multiplexer and DWDM Multiplexer?

Do you know these about CWDM Multiplexer and DWDM Multiplexer?

Wavelength division multiplexing (WDM) is a technology or technique modulating numerous data streams, i.e. optical carrier signals of varying wavelengths (colors) of laser light, onto a single optical fiber. The goal of WDM is to have a signal not to interfere with each other. It is usually used to make data transmission more efficiently. It has also been proven more cost effective in many applications, such as WDM network applications, broadband network application and fiber to the home (FTTH) applications and so on. According to channel spacing between neighbored wavelengths, there are two main types of WDM, including Coarse WDM (CWDM) and Dense WDM (DWDM). Though both of them belong to WDM technology, they are quite different. Then, what are the differences between them? This paper will give you the answer.

Definition of CWDM

CWDM is a method of combining multiple signals on laser beams at various wavelengths for transmission along fiber optic cables, such that the number of channels is fewer than in DWDM but more than in standard WDM. “Course” means the channel spacing is 20nm with a working channel passband of +/-6.5nm from the wavelengths center. From 1270nm to 1610nm, there are 18 individual wavelengths separated by 20nm spacing.

Definition of DWDM

DWDM is a technology that puts data from different sources together on an optical fiber, with each signal carried at the same time on its own separate light wavelength. “Dense” refers to the very narrow channel spacing measured in Gigahertz (GHz) as opposed to nanometer (nm). DWDM typically uses channel spacing of 100GHz with a working channel passband of +/-12.5GHz from the wavelengths center. It uses 200GHz spacing essentially skipping every other channel in the DWDM grid. And it has also gone one step further using an Optical Interleaver to get down to 50GHz spacing doubling the channels’ capacity from 100GHz spacing.

CWDM vs DWDM

According to the content above, you will find some small differences between them. 16CH CWDM Module is defined by wavelengths and has wide range channel spacing. DWDM is defined by frequencies and has narrow channel spacing. What’s more, what other differences do they have?

Capacity of Data

In fiber optic network system, DWDM system could fit more than 40 different data streams in the same amount of fiber used for two data streams in a CWDM system. In some cases, CWDM system can perform many of the same tasks compared to DWDM. Despite the lower transmission of data through a CWDM system, these are still viable options for fiber optic data transmission.

Cost of Cable

CWDM system carries less data, but the cabling used to run them is less expensive and less complex. A DWDM system has much denser cabling and can carry a significantly larger amount of data, but it can be cost prohibitive, especially where there is necessary to have a large amount of cabling in an application.

Long-haul or Short-haul Transmission

DWDM system is used for a longer haul transmission through keeping the wavelengths tightly packed. It can transmit more data over a significantly larger run of cable with less interference. However, CWDM system cannot travel long distances because the wavelengths are not amplified, and therefore CWDM is limited in its functionality over longer distances. If we neeed to transmit the data over a very long range, DWDM system solution may be the best choice in terms of functionality of the data transmission as well as the lessened interference over the longer distances that the wavelengths must travel. As far as cost is concerned, when required to provide signal amplification about 100 miles (160km), CWDM system is the best solution for short runs.

According to the content above, maybe you have already understood some differences between CWDM and DWDM by the comparision of them from definition, capacity, cable cost and transmission distance etc. And here is also a figure of comparisons between CWDM and DWDM which may help you to consolidate your understanding of this paper.

Tags: 19" rack mount chassis CWDM, ABS plastic box, CWDM MUX/DEMUX Module,  LGX CWDM Module,8CH CWDM Module, 16CH CWDM Module

Ultrafast laser pulses induce atoms in gold nanodisks to vibrate

In a study that could open doors for new applications of photonics from molecular sensing to wireless communications, Rice University scientists have discovered a new method to tune the light-induced vibrations of nanoparticles through slight alterations to the surface to which the particles are attached.

In a study published online this week in Nature Communications, researchers at Rice’s Laboratory for Nanophotonics (LANP) used ultrafast laser pulses to induce the atoms in gold nanodisks to vibrate. These vibrational patterns, known as acoustic phonons, have a characteristic frequency that relates directly to the size of the nanoparticle. The researchers found they could fine-tune the acoustic response of the particle by varying the thickness of the material to which the nanodisks were attached.

“Our results point toward a straightforward method for tuning the acoustic phonon frequency of a nanostructure in the gigahertz range by controlling the thickness of its adhesion layer,” said lead researcher Stephan Link, associate professor of chemistry and in electrical and computer engineering.

Rice University researchers (clockwise from front) Man-Nung Su, Wei-Shun Chang and Fangfang Wen discovered a new method to tune the light-induced vibrations of nanoparticles through slight alterations to the surface to which they are attached.

Light has no mass, but each photon that strikes an object imparts a miniscule amount of mechanical motion, thanks to a phenomenon known as radiation pressure. A branch of physics known as optomechanics has developed over the past decade to study and exploit radiation pressure for applications like gravity wave detection and low-temperature generation.

Link and colleagues at LANP specialize in another branch of science called plasmonics that is devoted to the study of light-activated nanostructures. Plasmons are waves of electrons that flow like a fluid across a metallic surface.

When a light pulse of a specific wavelength strikes a metal particle like the puck-shaped gold nanodisks in the LANP experiments, the light energy is converted into plasmons. These plasmons slosh across the surface of the particle with a characteristic frequency, in much the same way that each phonon has a characteristic vibrational frequency.

The study’s first author, Wei-Shun Chang, a postdoctoral researcher in Link’s lab, and graduate students Fangfang Wen and Man-Nung Su conducted a series of experiments that revealed a direct connection between the resonant frequencies of the plasmons and phonons in nanodisks that had been exposed to laser pulses.

“Heating nanostructures with a short light pulse launches acoustic phonons that depend sensitively on the structure’s dimensions,” Link said. “Thanks to advanced lithographic techniques, experimentalists can engineer plasmonic nanostructures with great precision. Based on our results, it appears that plasmonic nanostructures may present an interesting alternative to conventional optomechanical oscillators and high power isolator”

Chang said plasmonics experts often rely on substrates when using electron-beam lithography to pattern plasmonic structures. For example, gold nanodisks like those used in the experiments will not stick to glass slides. But if a thin substrate of titanium or chromium is added to the glass, the disks will adhere and stay where they are placed.

“The substrate layer affects the mechanical properties of the nanostructure, but many questions remain as to how it does this,” Chang said. “Our experiments explored how the thickness of the substrate impacted properties like adhesion and phononic frequency.”

Link said the research was a collaborative effort involving research groups at Rice and the University of Melbourne in Victoria, Australia.

“Wei-Shun and Man-Nung from my lab did the ultrafast spectroscopy,” Link said. “Fangfang, who is in Naomi Halas’ group here at Rice, made the nanodisks. John Sader at the University of Melbourne, and his postdoc Debadi Chakraborty calculated the acoustic modes, and Yue Zhang, a Rice graduate student from Peter Nordlander’s group at Rice simulated the optical/plasmonic properties. Bo Shuang of the Landes’ research group at Rice contributed to the analysis of the experimental data.”

The research was supported by the Robert A. Welch Foundation and the Department of Defense’s Multi-University Research Initiative. Additional co-authors include Zhang, Shuang, Nordlander and Halas, all of Rice; and Chakraborty and Sader, both of the University of Melbourne in Victoria, Australia.

About DK Photonics

DK Photonics – www.dkphotonics.com  specializes in designing and manufacturing of high quality optical passive components mainly for fiber laser applications such as 1064nm high power isolator, Cladding Power Stripper, Multimode High Power Isolator, pump combiner,1064nm Band-pass Filter,(6+1)X1 Pump and Signal Combiner, PM Circulator, PM Isolator, optical Coupler. More information, please contact us.

Polarization Dependent Isolator vs Polarization Independent Isolator

Connectors and other types of optical devices on the output of the transmitter may cause reflection, absorption, or scattering of the optical signal. These effects on the light beam may cause light energy to be reflected back at the source and interfere with source operation. In order to reduce the effects of the interference, an optical isolator is usually used. Optical isolator allows a beam of light to stream through a single one way direction. At the same time, it prevents the light from going back in the opposite direction. According to the polarization characteristics, optical isolators can be divided into two types, including polarization dependent isolator and polarization independent isolator. The polarizer-based module makes a polarization dependent isolator, and the birefringent crystal-based structure makes a polarization independent isolator. You may be very confused about them as you find that there is only a little difference via their names. So, what are they and what are the differences between them? This paper will give you the answer.

Polarization Dependent Isolator

The polarization dependent isolator consists of three parts, an input polarizer , a Faraday rotator, and an output polarizer. Light traveling in the forward direction becomes polarized vertically by the input polarizer. The Faraday rotator will rotate the polarization by 45°. The analyser then enables the light to be transmitted through the isolator.

Light traveling in the backward direction becomes polarized at 45° by the analyser. The Faraday rotator will again rotate the polarization by 45°. This means the light is polarized horizontally. Since the polarizer is vertically aligned, the light will be extinguished.

The picture shows us a Faraday rotator with an input polarizer, and an output analyser. For a polarization dependent isolator, the angle between the polarizer and the analyser, is set to 45°. The Faraday rotator is chosen to give a 45° rotation.

Because the polarization of the source is typically maintained by the system, polarization dependent isolator is widely used in free space optical systems.

Polarization Independent Isolator

The polarization independent isolator also consists of three parts, an input birefringent wedge, a Faraday rotator, and an output birefringent wedge. Light traveling in the forward direction is split by the input birefringent wedge into its vertical (0°) and horizontal (90°) components, called the ordinary ray (o-ray) and the extraordinary ray (e-ray) respectively. The Faraday rotator rotates both the o-ray and e-ray by 45°. This means the o-ray is now at 45°, and the e-ray is at −45°. The output birefringent wedge then recombines the two components.

Light traveling in the backward direction is separated into the o-ray at 45, and the e-ray at −45° by the birefringent wedge. The Faraday Rotator again rotates both the rays by 45°. Now the o-ray is at 90°, and the e-ray is at 0°. Instead of being focused by the second birefringent wedge, the rays diverge. The picture shows the propagation of light through a polarization independent isolator.

While polarization dependent isolator allows only the light polarized in a specific direction, polarization independent isolator transmit all polarized light. So it is usually widely used in optical fiber amplifier.

Comparison of Polarization Dependent Isolator and Polarization Independent Isolator

In fact, you have already understood these two types of isolators according to the contents above. We can see their similarities and differences through the comparison of their definition, working principle and applications. Both of them consist of three parts and have a same principle based on Faraday effect. However, to overcome the limitation of polarization dependent isolator, polarization independent isolator has been developed. Regardless of the polarization state of the input beam, the beam will propagate through the isolator to the output fiber and the reflected beam will be isolated from the optical source. If the extinction ratio is important, a polarization dependent isolator should be used with either polarization maintaining fibers or even regular single-mode fibers. If the system has no polarization dependence, a polarization independent isolator will be the obvious choice.

About DK Photonics

DK Photonics – www.dkphotonics.com  specializes in designing and manufacturing of high quality optical passive components mainly for fiber laser applications such as 1064nm high power isolator, Cladding Power Stripper, Multimode High Power Isolator, pump combiner,1064nm Band-pass Filter,(6+1)X1 Pump and Signal Combiner, PM Circulator, PM Isolator, optical Coupler. More information, please contact us.

2~18CH CWDM MUX/DEMUX Module from DK Photonics

The key components in a WDM system are the optical wavelength multiplexer (MUX), and the de-multiplexer (DEMUX). In general, a CWDM (coarse WDM) MUX/DEMUX deals with small numbers of wavelengths, typically eight, but with large spans between wavelengths (spaced typically at around 20nm). A DWDM (dense WDM) MUX/DEMUX deals with narrower wavelength spans (as small as 0.8nm, 0.4nm or even 0.2nm), and can accommodate 40, 80, or even 160 wavelengths.

The one kind of DK Photonics LGX CWDM MUX/DEMUX modules are bi-directional passive optical multiplexers and de-multiplexers, allowing multiple optical signals at different wavelengths to pass through a single optical fiber strand.

The second DK Photonics ABS CWDM MUX/DEMUX modules are duplex fiber link bi-directional multiplexers and de-multiplexers, allowing multiple optical signals’ at different wavelengths to pass through duplex optical fiber.

The last one kind is simplex directional CWDM MUX only or CWDM DEMUX only. The kind of mux and demux must be used with each other.

CWDM MUX/DEMUX solution lets operators make full use of available fiber bandwidth in local loop and enterprise architectures. Our CWDM MUX/DEMUX modules split up to 18 channels (20 nm spaced) to a single fiber. The standard packages are ABS Plastic Box, 19″ Rack Mount Chassis CWDM Mux/Demux  and LGX Metal Box Mux/Demux. No matter what kinds of connectors (such as FC, ST, SC, LC, etc.) are all available and we can also mix connectors on one device.

CWDM MUX+DEMUX 8 Channels (Dual Fiber) Module

DK Photonics offers a wide range of WDM (Wavelength Division Multiplexing) optical networking products that allow transport of any mix of services from 2Mbps up to 100Gbe over dark fiber and WDM networks providing for the entire set of the most demanding CWDM and DWDM network infrastructure needs.

2015-Optical Isolators Global Market Trends

According to ElectroniCast, the worldwide optical isolator consumption reached $584.2 million last year…. 

Aptos, California (USA) – March 2, 2015 -- ElectroniCast Consultants, a leading market research & technology forecast consultancy addressing the fiber optics communications industry, today announced the release of a new market forecast of the global consumption of optical isolators in optical communication and specialty applications.

According to ElectroniCast, the worldwide optical isolator consumption reached $584.2 million last year in 2014.  Optical isolator use was led by Telecommunication applications with a 72 percent market share or $419.2 million.  Market data in this study report refers to consumption (use) for a particular calendar year; therefore, this data is not cumulative data.

1064nm-High-Power-Collimated-Free-space-Beam-Output-Isolator

Optical isolators are devices that allow light to be transmitted in only one direction. They are most often used to prevent any light from reflecting back down the optical fiber, as this light would enter the source and cause backscattering and feedback problems. This is especially important for high data rate transceivers and transponders, or those devices requiring long span lengths between transceiver pairs. Optical feedback degrades signal-to-noise ratio and consequently bit-error rate.

1550nm Polarization Isensitive Isolator-300mW

“Continuing demand for upgrading communication networks to accommodate rapidly increasing bandwidth requirements will drive the steady consumption of optical fiber links. Optical isolators are used in with high-speed transmitters that are required to transmit longer distances and/or multiple wavelength transmitters,” stated Stephen Montgomery, Director of the Fiber Optics Components group at ElectroniCast Consultants.

Optical isolators are not widely used in Private Enterprise applications. The worldwide use of fiber optic isolators in Cable TV device deployments are forecast to grow in value at an annual rate of 4.9 percent (2014-2019), as optical fiber is deployed closer to the home driven by multi-media applications.

Optical isolator units are used in a variety of Military/Aerospace applications requiring rigorous testing and harsh environment fiber optic (HEFO) certification to ensure reliability and performance.  Laser-based fiber optic technology incorporating optical isolators are used in a wide variety of air, sea, ground, and space applications.

A major user-group within the Specialty application category is instrument-Laboratory/ R&D.  Optical isolators are used for noise reduction, medical imaging, pulse selection for mode locked lasers, sensing, regeneration switches, disc master, optical trapping, phase shifters, frequency modulation spectroscopy and general shuttering. The optical isolators are also used in sensing for industrial, structures and other many other communication product-oriented manufacturing/test/R&D uses.

DK Photonics – www.dkphotonics.com  specializes in designing and manufacturing of high quality optical passive components mainly for telecommunication, fiber sensor and fiber laser applications,such as 1064nm High Power Isolator,1064nm Components, PM Components, (2+1)x1 Pump Combiner,Pump Laser Protector,Mini-size CWDM,100GHz DWDM,Optical Circulator,PM Circulator,PM Isolator,Fused Coupler,Mini Size Fused WDM.

2015-Fiber Optic Circulators Global Market Analysis

The market value of fiber optic circulators increased 10.77% in 2014…

Aptos, CA (USA) – March 9, 2015 -- ElectroniCast Consultants, a leading market research & technology forecast consultancy addressing the fiber optics communications industry, today announced the release of a new market forecast of the global consumption of fiber optic circulators in optical communications.

During 2014-2019, the consumption value is forecast to increase with rising quantity growth partially offset by declining average prices.

The fiber optic circulator market is presented by the following port-count configurations: 3-Ports; 4-Ports; and more than 4-Ports (> 4 - Ports).  According to ElectroniCast, the worldwide use of fiber optic circulators reached $244.8 million in 2014, an increase of 10.77% over he total consumption value of $227.4 million in 2013.  3-Port fiber optic circulators held an 80% market share in 2014.  Well-over 70% of the 3-Port fiber optic circulator market value in 2014 was in Telecommunication applications.

Telecommunications is set to maintain its dominant market share lead throughout the forecast period.  Specialty applications (R&D laboratory, sensors, test equipment, oil/gas, other) are set to maintain the position of second-place, according to the ElectroniCast market forecast and analysis study.

Fiber Optic Circulators are non-reciprocal devices, which means that changes in the properties of light passing through the device are not reversed when the light passes through in the opposite direction. The optical device is commonly used in a wide variety of systems, here are just a few examples: dispersion compensation, optical sensors, optical amplifiers, WDM systems, optical add/drops multiplexing (OADMs) and test/measurement instruments such as optical time-domain reflectometers (OTDRs), remote fiber (optic) test systems (RFTS) and other test equipment.

The deployment of optical fiber in the metro/access, the continuing demand for upgrading networks to accommodate rapidly increasing bandwidth requirements, plus the need for additional monitoring and testing of the optical fiber networks will drive the steady consumption of fiber optic circulators.

According to ElectroniCast Consultants, 3-Port fiber optic circulators held an 80% (value) market share in 2014…

Fiber Optic Circulator Global Market Share (%), By Port Count

(2014 – ElectroniCast Estimate: $244.8 Million)

DK Photonics – www.dkphotonics.com  specializes in designing and manufacturing of high quality optical passive components mainly for telecommunication, fiber sensor and fiber laser applications,such as 1064nm High Power Isolator,1064nm Components, PM Components, (2+1)x1 Pump Combiner,Pump Laser Protector,Mini-size CWDM,100GHz DWDM,Optical Circulator,PM Circulator,PM Isolator,Fused Coupler,Mini Size Fused WDM.

Introduction of the Transients in Optical WDM Networks

A systems analysis continues to be completed to consider dynamical transient effects in the physical layer of an Optical WDM Network. The physical layer dynamics include effects on different time scales. Dynamics from the transmission signal impulses possess a scale of picoseconds. The timing recovery loops in the receivers be employed in the nanoseconds time scale. Optical packet switching in the future networks will have microsecond time scale. Growth and development of such optical networks is yet continuing. Most of the advanced development work in optical WDM networks is presently focused on circuit switching networks, where lightpath change events (for example wavelength add/drop or cross-connect configuration changes) happen on the time scale of seconds.

It is focused on the dynamics from the average transmission power associated with the gain dynamics in Optical Line Amplifiers (OLA). These dynamics may be triggered by the circuit switching events and have millisecond time scale primarily defined by the Amplified Spontaneous Emission (ASE) kinetics in Erbium-Doped Fiber Amplifiers (EDFAs). The transmission power dynamics will also be influenced by other active components of optical network, for example automatically tunable 100GHz DWDM, spectral power equalizers, or other light processing components. When it comes to these dynamics, a typical power of the lightpath transmission signal is recognized as. High bandwidth modulation from the signal, which actually consists of separate information carrying pulses, is mostly ignored.

14-nodes Ring WDMRing WDM networks implementing communication between two fixed points are very well established technology, in particular, for carrying SONET over the WDM. Such simple networks with fixed WDM lighpaths happen to be analyzed in many detail. Fairly detailed first principle models for transmission power dynamics exist for such networks. These models are implemented in industrial software allowing engineering design calculations and dynamical simulation of these networks. Such models could possibly have very high fidelity, but their setup, tuning (model parameter identification) and exhaustive simulations covering a variety of transmission regimes are potentially very labor intensive. Adding description of new network components to such model could need a major effort.

14-nodes Mesh WDMThe problems with detailed first principle models is going to be greatly exacerbated for future Mesh WDM networks. The near future core optical networks will be transparent to wavelength signals on a physical layer. In such network, each wavelength signal travels through the optical core between electronic IP routers around the optical network edge using the information contents unchanged. The signal power is attenuated in the passive network elements and boosted by the optical amplifiers. The lightpaths is going to be dynamically provisioned by Optical Cross-Connects (OXCs), routers, or switches independently on the underlying protocol for data transmission. Such network is basically a circuit switched network. It might experience complex transient processes of the average transmission power for every wavelength signal at the event of the lightpath add, drop, or re-routing. A mix of the signal propagation delay and channel cross-coupling might result in the transmission power disturbances propagating across the network in closed loops and causing stamina oscillations. Such oscillations were observed experimentally. Additionally, the transmission power and amplifier gain transients could be excited by changes in the average signal power because of the network traffic burstliness. If for some period of time the wavelength channel bandwidth is not fully utilized, this could result in a loss of the average power (average temporal density of the transmitted information pulses).

First circuit switched optical networks are already being designed and deployed. Fraxel treatments develops rapidly for metro area and long term networks. Engineering design of circuit switched networks is complicated because performance has to be guaranteed for all possible combinations of the lightpaths. Further, as such networks develop and grow, they potentially need to combine heterogenous equipment from a variety of vendors. A system integrator (e.g., DK Photonics) of such network might be different from subsystems or component manufacturer. This creates a necessity of developing adequate means of transmission power dynamics calculations which are suitable for the circuit switched network business. Ideally, these methods should be modular, independent on the network complexity, and use specifications on the component/subsystem level.

DK Photonics has technical approach to systems analysis that’s to linearize the nonlinear system around a fixed regime, describe the nonlinearity like a model uncertainty, and apply robust analysis that guarantees stability and gratifaction conditions within the presence of the uncertainty. For a user of the approach, there is no need to understand the derivation and system analysis technicalities. The obtained results are very simple and relate performance to basic specifications of the network components. These specifications are somewhat not the same as those widely used in the industry, but could be defined from simple experimentation using the components and subsystems. The obtained specification requirements may be used in growth and development of optical amplifiers, equalizers, optical attenuators, other transmission signal conditioning devices, OADM Modules, OXCs, and any other optical network devices and subsystems influencing the transmission power.

DK Photonics – www.dkphotonics.com  specializes in designing and manufacturing of high quality optical passive components mainly for telecommunication, fiber sensor and fiber laser applications,such as WDM, FWDM, CWDM, DWDM, OADM,Optical Circulator, Isolator, PM Circulator, PM Isolator, Fused Coupler, Fused WDM, Collimator, Optical Switch and Polarization Maintaining Components, Pump Combiner, High power isolator, Patch Cord and all kinds of connectors.

A systems analysis continues to be completed to consider dynamical transient effects in the physical layer of an Optical WDM Network. The physical layer dynamics include effects on different time scales. Dynamics from the transmission signal impulses possess a scale of picoseconds. The timing recovery loops in the receivers be employed in the nanoseconds time scale. Optical packet switching in the future networks will have microsecond time scale. Growth and development of such optical networks is yet continuing. Most of the advanced development work in optical WDM networks is presently focused on circuit switching networks, where lightpath change events (for example wavelength add/drop or cross-connect configuration changes) happen on the time scale of seconds.

It is focused on the dynamics from the average transmission power associated with the gain dynamics in Optical Line Amplifiers (OLA). These dynamics may be triggered by the circuit switching events and have millisecond time scale primarily defined by the Amplified Spontaneous Emission (ASE) kinetics in Erbium-Doped Fiber Amplifiers (EDFAs). The transmission power dynamics will also be influenced by other active components of optical network, for example automatically tunable 100GHz DWDM, spectral power equalizers, or other light processing components. When it comes to these dynamics, a typical power of the lightpath transmission signal is recognized as. High bandwidth modulation from the signal, which actually consists of separate information carrying pulses, is mostly ignored.

14_nodes Ring WDMRing WDM networks implementing communication between two fixed points are very well established technology, in particular, for carrying SONET over the WDM. Such simple networks with fixed WDM lighpaths happen to be analyzed in many detail. Fairly detailed first principle models for transmission power dynamics exist for such networks. These models are implemented in industrial software allowing engineering design calculations and dynamical simulation of these networks. Such models could possibly have very high fidelity, but their setup, tuning (model parameter identification) and exhaustive simulations covering a variety of transmission regimes are potentially very labor intensive. Adding description of new network components to such model could need a major effort.

14_nodes Mesh WDMThe problems with detailed first principle models is going to be greatly exacerbated for future Mesh WDM networks. The near future core optical networks will be transparent to wavelength signals on a physical layer. In such network, each wavelength signal travels through the optical core between electronic IP routers around the optical network edge using the information contents unchanged. The signal power is attenuated in the passive network elements and boosted by the optical amplifiers. The lightpaths is going to be dynamically provisioned by Optical Cross-Connects (OXCs), routers, or switches independently on the underlying protocol for data transmission. Such network is basically a circuit switched network. It might experience complex transient processes of the average transmission power for every wavelength signal at the event of the lightpath add, drop, or re-routing. A mix of the signal propagation delay and channel cross-coupling might result in the transmission power disturbances propagating across the network in closed loops and causing stamina oscillations. Such oscillations were observed experimentally. Additionally, the transmission power and amplifier gain transients could be excited by changes in the average signal power because of the network traffic burstliness. If for some period of time the wavelength channel bandwidth is not fully utilized, this could result in a loss of the average power (average temporal density of the transmitted information pulses).

First circuit switched optical networks are already being designed and deployed. Fraxel treatments develops rapidly for metro area and long term networks. Engineering design of circuit switched networks is complicated because performance has to be guaranteed for all possible combinations of the lightpaths. Further, as such networks develop and grow, they potentially need to combine heterogenous equipment from a variety of vendors. A system integrator (e.g., DK Photonics) of such network might be different from subsystems or component manufacturer. This creates a necessity of developing adequate means of transmission power dynamics calculations which are suitable for the circuit switched network business. Ideally, these methods should be modular, independent on the network complexity, and use specifications on the component/subsystem level.

DK Photonics has technical approach to systems analysis that’s to linearize the nonlinear system around a fixed regime, describe the nonlinearity like a model uncertainty, and apply robust analysis that guarantees stability and gratifaction conditions within the presence of the uncertainty. For a user of the approach, there is no need to understand the derivation and system analysis technicalities. The obtained results are very simple and relate performance to basic specifications of the network components. These specifications are somewhat not the same as those widely used in the industry, but could be defined from simple experimentation using the components and subsystems. The obtained specification requirements may be used in growth and development of optical amplifiers, equalizers, optical attenuators, other transmission signal conditioning devices, OADM Modules, OXCs, and any other optical network devices and subsystems influencing the transmission power.

DK Photonics – www.dkphotonics.com  specializes in designing and manufacturing of high quality optical passive components mainly for telecommunication, fiber sensor and fiber laser applications,such as WDM, FWDM, CWDM, DWDM, OADM,Optical Circulator, Isolator, PM Circulator, PM Isolator, Fused Coupler, Fused WDM, Collimator, Optical Switch and Polarization Maintaining Components, Pump Combiner, High power isolator, Patch Cord and all kinds of connectors.

How To Test Fiber Optic Splitters Or Other Passive Devices

A fiber optic splitter is a device that splits the fiber optic light into several parts by a certain ratio. For example, when a beam of fiber optic light transmitted from a 1X4 equal ratio splitter, it will be divided into 4-fiber optic light by equal ratio that is each beam is 1/4 or 25% of the original source one. A Optical Splitter is different from WDM. WDM can divide the different wavelength fiber optic light into different channels. fiber optic splitter divide the light power and send it to different channels.

Most Splitters available in 900µm loose tube and 250µm bare fiber. 1×2 and 2×2 couplers come standard with a protective metal sleeve to cover the split. Higher output counts are built with a box to protect the splitting components.

Testing a coupler or splitter (both names are used for the same device) or other passive fiber optic devices like switches is little different from testing a patchcord or cable plant using the two industry standard tests, OFSTP-14 for double-ended loss (connectors on both ends) or FOTP-171 for single-ended testing.

First we should define what these passive devices are. An optical coupler is a passive device that can split or combine signals in optical fibers. They are named by the number of inputs and outputs, so a splitter with one input and 2 outputs is a 1×2 fiber splitter, and a PON splitter with one input and 32 outputs is 1×32 splitter. Some PON splitters have two inputs so it would be a 2X32. Here is a table of typical losses for splitters.

Important Note! Mode Conditioning can be very important to testing couplers. Some of the ways they are manufactured make them very sensitive to mode conditioning, especially multimode but even singlemode couplers. Singlemode couplers should always be tested with a small loop in the launch cable (tied down so it does not change and set the 0dB reference with the loop.) Multimode couplers should be mode conditioned by a mandrel wrap or similar to ensure consistency.

Let’s start with the simplest type. Shown below is a simple 1X2 splitter with one input and two outputs. Basically, in one direction it splits the signal into 2 parts to couple to two fibers. If the split is equal, each fiber will carry a signal that is 3dB less than the input (3dB being a factor of two) plus some excess loss in the coupler and perhaps the connectors on the splitter module. Going the other direction, signals in either fiber will be combined into the one fiber on the other side. The loss is this direction is a function of how the coupler is made. Some couplers are made by twisting two fibers together and fusing them in high heat, so the coupler is really a 2X2 coupler in which case the loss is the same (3dB plus excess loss) in either direction. Some splitters use optical integrated components, so they can be true splitters and the loss in each direction may different.

So for this simple 1X2 splitter, how do we test it? Simply follow the same directions for a double-ended loss test. Attach a launch reference cable to the test source of the proper wavelength (some splitters are wavelength dependent), calibrate the output of the launch cable with the meter to set the 0dB reference, attach to the source launch to the splitter, attach a receive launch cable to the output and the meter and measure loss. What you are measuring is the loss of the splitter due to the split ratio, excess loss from the manufacturing process used to make the splitter and the input and output connectors. So the loss you measure is the loss you can expect when you plug the splitter into a cable plant.

To test the loss to the second port, simply move the receive cable to the other port and read the loss from the meter. This same method works with typical PON splitters that are 1 input and 32 outputs. Set the source up on the input and use the meter and reference cable to test each output port in turn.

What about the other direction from all the output ports? (In PON terms, we call that upstream and the other way from the 1 to 32 ports direction downstream.) Simply reverse the direction of the test. If you are tesing a 1X2 splitter, there is just one other port to test, but with a 1X32, you have to move the source 32 times and record the results on the meter.

What about multiple input and outputs, for example a 2X2 coupler? You would need to test from one input port to the two outputs, then from the other input port to each of the two outputs. This involves a lot of data sometimes but it needs to be tested.

There are other tests that can be performed, including wavelength variations (test at several wavelengths), variations among outputs (compare outputs) and even crosstalk (put a signal on one output and look for signal on other outputs.)

Once installed, the splitter simply becomes one source of loss in the cable plant and is tested as part of that cable plant loss for insertion loss testing. Testing splitters with an OTDR is not the same in each direction.

Other Passive Devices

There are other passive devices that require testing, but the test methods are similar.

Fiber optic switches are devices that can switch an input to one of several outputs under electronic control. Test as you would the splitter as shown above. Switches may be designed for use in only one direction, so check the device specifications to ensure you test in the proper direction. Switches may also need testing for consistency after multiple switch cycles and crosstalk.

Attenuators are used to reduce signal levels at the receiver to prevent overloading the receiver. There is a page on using attenuators that you should read. If you need to test an attenuator alone, not part of a system, use the test for splitters above by using the attenuator to connect the launch and receive cables to see if the loss is as expected.

Wavelength-division multiplexers can be tricky to test because they require sources at a precise wavelenth and spectral width, but otherwise the test procedures are similar to other passive components.

Fiber optic couplers or splitters are available in a wide range of styles and sizes to split or combine light with minimal loss. All couplers are manufactured using a very simple proprietary process that produces reliable, low-cost devices. They are physically rugged and insensitive to operating temperatures. Couplers can be fabricated in custom fiber lengths and/or with terminations of any type.

DK Photonics – www.dkphotonics.com  specializes in designing and manufacturing of high quality optical passive components mainly for telecommunication, fiber sensor and fiber laser applications,such as PLC Splitter, WDM, FWDM, CWDM, DWDM, OADM,Optical Circulator, Isolator, PM Circulator, PM Isolator, Fused Coupler, Fused WDM, Collimator and Polarization Maintaining Components, Pump Combiner, High power isolator, Patch Cord and all kinds of connectors.

Optical Filters: Filter stacks transmit wide-angle incident light without shifting wavelength(3)

To avoid the problem of color change versus incidence angle in an optical system, thin-film-coated filter elements can be replaced by a filter consisting of a stack of different filter glasses.

JASON KECK

Rugged, no coating degradation

Advantages of using a filter stack rather than a thin-film-coated optical element include wide-angle performance (see Fig. 2) and high durability. Because the glass itself performs the blocking, there is no concern of coating degradation due to extreme environmental shifts, contamination, or mishandling. Filter stacks are as durable as the glass they are made from, surviving aggressive cleaning methods, severe abrasion, salt/fog testing, humidity, and temperature cycling per durability standards of MIL-PRF-13830B, MIL-C-48497A, and MIL-C-675C.

Because all filter glass types have approximately the same index of refraction, there is no Fresnel loss as light propagates from one internal layer to another. However, as with any glass, the air-to-substrate interfaces will incur an ~8% total Fresnel loss for the component.

The addition of a broadband antireflection (BBAR) coating on each air-to-substrate surface can mostly eliminate this loss. The spectral range of the BBAR is designed to be much wider than the active spectral region of the 100G DWDM filter, so the stability of the transmission band will not be affected by changes in the angle of the filter. Blocking coatings can also be added if it is necessary to create steeper edges for in-band performance; however, doing so can affect the wide-angle performance at the edge wavelengths.

ColorLock filter stacks can be designed for spectral ranges from ultraviolet to near-infrared, with transmission exceeding 60% at the specified design wavelength. This transmission may not be as high as with dielectric filters, but is sufficient for applications with controlled and stable illumination, such as for machine vision, in which the consistency of wavelengths from wider incident angles is more important than transmission.

Having overcome considerable design challenges, we believe that these filter stacks can be used as an innovative solution in applications that demand consistent wavelengths from incident angles that are wide enough that dielectric filters would not be sufficient, and where the higher transmission that is afforded by dielectric filters is less important.

DK Photonics – www.dkphotonics.com  specializes in designing and manufacturing of high quality optical passive components mainly for fiber laser applications such as 1064nm high power isolator, Cladding Power Stripper, Multimode High Power Isolator, pump combiner,1064nm Band-pass Filter,(6+1)X1 Pump and Signal Combiner, PM Circulator, PM Isolator, optical Coupler. More information, please contact us.

Optical Filters: Filter stacks transmit wide-angle incident light without shifting wavelength(2)

To avoid the problem of color change versus incidence angle in an optical system, thin-film-coated filter elements can be replaced by a filter consisting of a stack of different filter glasses.

JASON KECK

Wide-angle filter stack apps

There is a multitude of applications for this type of filter. In the field of digital imaging, colorimeters-which take wideband spectral energy readings-are used to profile and calibrate display devices, verifying that pixel color and intensity at the edge of a display matches the performance of pixels in the center of the display.

In astronomy, biomedical or fluorescence imaging, and mineralogy, hyperspectral imaging has many important applications. It is essential that the incident light undergo as little iridescence as possible. Also, when precision imaging instruments are expensively launched into orbit, the filters must be robust enough to withstand extreme environmental operating conditions.

In agriculture, the color of crops or food products reveals vital information. The use of Earth-observing satellites to measure the "vegetation index" of crops (a measurement of green hue) is nothing new, but the affordability of aerial drones has brought new possibilities. A drone can be programmed with GPS data to fly on a fixed pattern over a designated crop area and take wide-angle images at regular intervals, building up a picture of the vegetation index of crops. If the images used in such applications provide accurate spectral data that is as free as possible from iridescent distortion, it can give farmers precise control over fertilizer application rates and greatly improve efficiency and productivity. This is a considerable cost saving over low-resolution, narrowband satellite imagery and conventional aerial photography using manned aircraft.

Design hurdles

There are three complicating factors in the design of such filter stacks. The first is the limited choice in filter glass, limited not only by manufacturer availability but also by physics. Filter glass with an ideal edge cut-on or cut-off wavelength for an application is not always easy to find, or may be impossible to precisely manufacture. Where it is available, the designer is then limited by what the manufacturer can deliver in a reasonable time, as melts may be scheduled as infrequently as once every several years, depending on demand.

The second factor is that, while the perfect filter glass for a particular application may not exist, there are hundreds of other glass types from numerous vendors that can be combined to achieve a close approximation of the requirement.

The third complicating factor is that the design of ColorLock filters is a massively multidimensional, nonsmooth optimization challenge. Physical manufacturing requirements restrict the thickness of all combined individual layers to not exceed the overall thickness requirement of the resulting optical component, further putting restrictions on the selection of specific CWDM filter glass types.

Reynard streamlined this complex design process by developing in-house software into which all of the system requirements are fed. The software produces a manufacturable design for a filter in which the necessary materials are combined at the correct thickness in each layer. The design is then manufactured and validated for performance.

About DK Photonics

DK Photonics – www.dkphotonics.com  specializes in designing and manufacturing of high quality optical passive components such as 8CH CWDM Module,100GHz 8CH DWDM,200GHz DWDM,Mini-size CWDM,compact CWDM,Athermal AWG DWDM Module,100GHz AWG,Thermal AWG DWDM Module,1310/1490/1550nm FWDM, PLC Splitter, Optical Circulator,Optical Isolator,Fused Coupler,Mini Size Fused WDM.

Optical Filters: Filter stacks transmit wide-angle incident light without shifting wavelength(1)

To avoid the problem of color change versus incidence angle in an optical system, thin-film-coated filter elements can be replaced by a filter consisting of a stack of different filter glasses.

JASON KECK

Wide-angle imaging systems have to overcome numerous problems. Distortion of the shape of objects in the scene is the predominant issue, recognizable as the "fish-eye lens" look that is often corrected in software. However, lens distortion is not the only problem.

Iridescence, or the change in transmitted or reflected color of light viewed from different angles, is a phenomenon that can be found both in nature and in artificial light-detecting systems with precise color requirements, where it can cause many problems.

Wide-angle color-sensing applications commonly require that a CWDM wavelength must be detectable regardless of the incident angle. Iridescence through a thin-film-coated optical element can cause problems in this situation by distorting the spectral transmission of light coming from peripheral objects.

Maximizing light transmission in a thin-film WDM coating's passband while blocking out-of-band light is a requirement for coated optical components such as dielectric filters; however, the wavelength's transition commonly only remains steady within relatively narrow cone angles. Beyond angles of 5°, such filters are susceptible to iridescence, observable as a change of color, or "blueshift." As the angle of light entering the filter increases, the light propagates through more of each thin-film stack layer, altering the apparent overall thickness of the optical-filter stack and affecting the performance of the original intended design. This can make such filters unsuitable for wide-angle imaging applications with bright illumination and where higher standards of consistency are required of the wavelength of all incident light.

One of the more convoluted wide-angle imaging solutions is the use of a cluster of cameras or a polycamera, pointing in various directions like the compound eye of an insect; the resulting multiple pictures are then assembled into one image in software. Although the light entering each camera thus fills only a narrow cone angle, the complexity and resultant high expense of such a system is obvious.

Engineers at Reynard have addressed this problem in a single optical device with a system in which two or more layers of filter glass are combined into a stacked configuration. These ColorLock filter stacks eliminate the wavelength shift as incident angle increases and are customized to meet specific system needs.

Software is used to determine the exact composition and thickness of the layers in these filters; the software determines a merit function that best estimates the filter requirements and allows filter stacks to be designed for band pass, short-wave pass, long-wave pass, or user-specified functions. Incident angles can be as high as 50° without any shift in the transmitted wavelength, while more traditional coated filters with the same conditions would see a significant shift toward shorter wavelengths.

About DK Photonics

DK Photonics – www.dkphotonics.com  specializes in designing and manufacturing of high quality optical passive components such as 8CH CWDM Module,100GHz 8CH DWDM,200GHz DWDM,Mini-size CWDM,compact CWDM,Athermal AWG DWDM Module,100GHz AWG,Thermal AWG DWDM Module,1310/1490/1550nm FWDM, PLC Splitter, Optical Circulator,Optical Isolator,Fused Coupler,Mini Size Fused WDM.

Pump and signal combiner for bi-directional pumping of all-fiber lasers and amplifiers(7)

Pump and signal combiner for bi-directional pumping of all-fiber lasers and amplifiers(7)

5. Simulations and results for a multi pump port configuration

So far, the modeling results consider a TF with only a single pump port. However, for monolithic high power fiber laser and amplifier systems, it is often required to provide multiple pump ports due to the limited output power of available fiber coupled pump diodes and the efforts to develop laser systems with redundancy. Thus, in this section, we investigate the impact of multiple pump ports on the coupling efficiency and the loss mechanism. The setup of each pump combiner is identical to the description in Section 2 (see Fig. 1), but with several additional ports placed around the cladding of the TF, leading to a fiber bundle. A schematic of a fiber combiner with multiple pump ports is shown in Fig. 7

Fig. 7 Fiber combiner with multiple pump ports, PFF: pump feeding fiber with a piece of coreless intermediate fiber (IF) as described in Fig. 1, TF: target fiber, TP: transmitted power.

5.1 Simulations of the pump coupling efficiency

The experiments and simulations in Section 4 showed that for a pump combiner with a single pump port, a TL of 20 mm and a TR of 6 yields an excellent coupling efficiency in the range of 95%. In comparison, for a fiber band pass filter with multiple pump ports, the simulations for a TL of 20 mm (Fig. 8(a)

Fig. 8 Simulated coupling efficiency for a pump combiner with up to 6 pump ports for (a) a TL of 20 mm and (b) a TL of 10 mm for a pump light input NA of 0.22.

) revealed that the pump coupling efficiency of the combined pump power depends on the number of pump ports and significantly on the choice of the TR. In the simulations the input pump light NA of the PFFs was 0.22. In general, it can be seen that the pump coupling efficiency decreases with each additional pump port. A lower TR yields a greater decrease of the pump coupling efficiency with each additional pump port than a higher TR. In the case of a TL of 20 mm and a TR of 2.5, the theoretically obtainable pump coupling efficiency of almost 90% decreases to 73%, if the number of pump ports increases from 1 to 6. However, as already mentioned, the increasing losses due to additional pump ports can be reduced with increasing TR. In Fig. 8(a) it can be clearly observed that for 6 pump ports and a TR of 6, a pump coupling efficiency of 90.2% can be achieved. For a TR higher than 6, it is not possible to achieve a significant improvement in pump coupling efficiency for multiple pump ports by increasing of the TR.

For a single pump port configuration it is already known that the pump coupling efficiency decreases with shorter TLs at constant TRs (Fig. 2(a)). However, for multiple pump ports a reduction of the TL leads to the advantage that the pump coupling efficiency of the combined pump power decreases less with each additional pump port, especially at lower TRs. The simulation results for a TL of 10 mm instead of a TL of 20 mm are presented in Fig. 8(b). A comparison of Fig. 8(a) and 8(b) shows: If the number of pump ports is increased from 1 to 6 at a TR of 2.5, the pump coupling efficiency experiences a decrease of 16.9 and 11.2% for a TL of 20 and 10 mm, respectively. Although the total power losses for a TL of 10 mm are higher than for a TL of 20 mm, the example reveals, that the decrease of the pump coupling efficiency due to additional pump ports can be reduced by using shorter TLs.

Besides having less available combined pump power, the additional pump power losses generated in comparison to a fiber combiner with a single pump port, corresponds to an enhanced risk of damaging the component due to additional thermal load. Hence, the loss mechanism for a fiber combiner with multiple pump ports needs to be investigated in more detail.

About DK Photonics

DK Photonics – www.dkphotonics.com  specializes in designing and manufacturing of high quality optical passive components mainly for fiber laser applications such as 1064nm high power isolator, Cladding Power Stripper, Multimode High Power Isolator, pump combiner,1064nm Band-pass Filter,(6+1)X1 Pump and Signal Combiner, PM Circulator, PM Isolator, optical Coupler. More information, please contact us.

Industrial Fiber Laser Introduction and Global Market Forecast –DK Photonics

The Global Industrial Fiber Laser market to grow at a CAGR of 21.4% over the period 2013-2018

Fiber lasers contain the active gain medium, which is an optical fiber integrated with rare earth elements such as erbium and ytterbium. Unlike conventional gas lasers, a fiber laser uses part of the fiber as the resonating cavity, where the laser action takes place to generate laser beams , Fiber lasers are preferred over other lasers such as CO2 lasers and excimer lasers, primarily because they are more reliable, efficient, robust, and portable, and easier to operate than other lasers.

Fiber lasers used for industrial applications such as cutting, welding, marking, and engraving in the Manufacturing, Semiconductor, and Automotive industries are referred to as industrial fiber lasers. Moreover, due to their superior performance, compact size, high output power, low cost of ownership, durability, and eco-friendly attributes, industrial fiber lasers are being adopted at a significant rate. They also eliminate the mechanical adjustments and high maintenance costs that are necessary with other lasers.

Increased R&D spending by vendors to gain a competitive advantage over other players in the market is one key trend in this market. Vendors are increasingly investing in their R&D division to provide better functionality and to meet the unsatisfied requirements of consumers. R&D investments have enabled vendors to capture a significant market share and gain a competitive edge over other vendors in the Global Industrial Fiber Laser market.

According to the report, one major driver of the market is the increased adoption of fiber lasers because of their superior attributes. These lasers used for industrial applications are gaining more significance because they exhibit excellent light properties.

Further, the report states that one of the key challenges that the market faces is the uncertainty regarding the lifespan of fiber lasers. Despite their existence in the industry for more than 10 years, the lifespan fiber lasers are not definite.

DK Photonics – www.dkphotonics.com  specializes in designing and manufacturing of high qualityoptical passive components mainly for fiber laser applications such as 1064nm high power isolator, Cladding Power Stripper, Multimode High Power Isolator, pump combiner,1064nm Band-pass Filter,(6+1)X1 Pump and Signal Combiner, PM Circulator, PM Isolator, optical Coupler. More information, please contact us.

Pump and signal combiner for bi-directional pumping of all-fiber lasers and amplifiers(6)

Pump and signal combiner for bi-directional pumping of all-fiber lasers and amplifiers(6)

4.4 Experimental results

In order to verify the simulations, two fiber combiners with a single pump port based on the setup described in Section 2 were developed. For the first combiner an IF with a low TR of 2.6 and a short TL of 9.5 mm was fabricated. In the case of the second combiner the TR and the TL were increased to 6.7 and 18 mm, respectively. For both combiners the geometrical dimensions of the obtained tapered IFs were measured with an optical microscope. After completion of the fabrication, both combiners were optically characterized. Therefore, each PFF (pump port) with a NA of 0.15 was connected to a pump diode (Oclaro BMU25) with a pigtail fiber delivering a maximum output power of ~25 W at a wavelength of 976 nm. The delivery fiber of the pump diode had parameters identical to the PFF.

The experimental results for the first fiber combiner are shown in Fig. 6(a)

Fig. 6 Coupled and transmitted power measured for a fiber combiner with one pump port with (a) a TL of 9.5 mm (TR of 2.6) and (b) a TL of 18 mm (TR 6.7), * ratio of coupled or transmitted power to total diode power in percent.

. Due to the low TR of 2.6, an experimental pump coupling efficiency of only 74% was achieved. The residual pump power was almost completely measured as TP, with a power fraction of 25.3%. The simulations for the coupled as well as the TP show good agreement with the experimental results, and confirm that in the case of a low TR of 2.6, the pump power is only divided into coupled power and TP. In Fig. 6(a) it can be seen that in the simulations the sum of the coupled and TP is 99.9%, corresponding to 0.1% of pump light rays not detected in the simulations. This can be treated as a simulation error. That the measured sum of coupled pump power and TP is only 99.3% can be explained by measurement uncertainties, marginal splice losses and additional power losses in the fiber component caused by dust particles. Since the thermal load of this fiber combiner design is negligible it would be feasible to couple several kW of pump power, but with the disadvantage of a moderate coupling efficiency of about 75% and consequently a undesirable overall efficiency for high power laser system.

For the second fiber combiner, depicted in Fig. 6(b), a higher pump coupling efficiency of 95.2% (96.0% in simulation) was measured as compared to the first combiner presented in Fig. 6(a) due to the increase in TR and TL. Following the simulations the residual pump power of 4% can be divided into TP, PCT and PAA with 2.4%, 0.6% and 0.9%, respectively. Again, the missing pump power of 0.1% was associated with an error owing to undetected power in the simulations. For the TP a fraction of 2.3% was measured and shows very good agreement with the simulation (2.4%), i.e. more than 50% of the total power loss was TP. This fraction of power represents no risk for damage to the fiber component. Due to the excellent agreement between simulation and experiment, the simulated PCT-fraction of only 0.6% is a good value for an estimate of the thermal load of the coating of the TF. Based on the simulations and experiments an error of less than 1% of the pump input power can be assumed for the PCT-fraction.

Unfortunately, the power fractions PAA and PCT are difficult to measure and therefore could not be experimentally determined. In future work an indirect measurement of PCT will be realized by measuring the coating temperature of the CWDM Module. In summary, the simulations describe the coupling efficiency as well as the fraction of TP very well, and thus, serve as a very good estimation for the fraction of PCT and PAA.

DK Photonics – www.dkphotonics.com  specializes in designing and manufacturing of high quality optical passive components mainly for telecommunication, fiber sensor and fiber laser applications,such as PLC Splitter, WDM, FWDM, CWDM, DWDM, OADM,Optical Circulator, Isolator, PM Circulator, PM Isolator, Fused Coupler, Fused WDM, Collimator, Optical Switch and Polarization Maintaining Components, Pump Combiner, High power isolator, Patch Cord and all kinds of connectors.

DK Photonics:Huawei to invest over $4 billion in fixed broadband technology in 3 years

Telecom network vendor Huawei on Thursday said it will be investing over $4 billion in fixed broadband (FBB) technology research and development over the next three years.

Huawei’s plans to invest significantly in fixed broadband technology reflects a report from Dell’Oro Group that said wireline telecom markets will grow at a CAGR of 3 percent against 1 percent growth for wireless between 2013 and 2018.

In August, Dell’Oro Group said the combined service provider equipment markets will grow at a CAGR of 2 percent between 2013 and 2018 — after recording a CAGR of -1 percent between 2008 and 2013.

Huawei said the $4 billion investment will focus on products and solutions which will support their customers with providing an improved service experience for end users.

Huawei Products and Solutions President Ryan Ding said: “Our investment will further develop technological advances, help customers increase their competitiveness and decrease overall operating costs.”

Existing technologies are changing, next-generation High-Efficiency Video Coding is maturing, 4k panel and content production costs are reducing and the development of the 4k video industry, are all driving new solutions.

As LTE and 5G deployment continues, construction of high-performance networks which guarantee better customer experience will be expected by telecom operators. Huawei said FBB technologies will be progressed by leveraging big data, data centers and cloud computing to meet their needs.

Tam Dell’Oro, president and founder of Dell’Oro Group, said: “While we believe carriers will continue to enhance their wireless networks, we anticipate carriers will put more emphasis on backhauling traffic which means improving their fixed line networks in the next five years.”

Huawei today said it will innovate Software Defined Networking (SDN), Network Functions Virtualization (NFV) to initiate open broadband networks that help customers simplify operations and management, realize service innovation and improve network efficiency.

For next-generation networks, Huawei will conduct research and develop on new key technologies and architectures for IP and all-optical networks, advancing FBB network development.

Fixed LTE broadband access gains

At present, 1.26 billion households do not have DSL, cable, or fiber-optic broadband. Fixed and mobile telecoms are looking to LTE to make the connection.

“By the end of 2014, there will be 14.5 million residential and commercial premises with fixed LTE broadband access. By 2019, that figure should grow to 123 million,” said Jake Saunders, VP and 4G practice director at ABI Research.

ITU pitches for broadband

ITU, a telecom industry association under the aegis of UN, says more than 40 percent of the world’s people are already online, with the number of Internet users rising from 2.3 billion in 2013 to 2.9 billion by the end of this year.

Over 2.3 billion people will access mobile broadband by end 2014, climbing steeply to a predicted 7.6 billion within the next five years.

ITU says there are now over three times as many mobile broadband connections as there are conventional fixed broadband subscriptions.

Huawei on green telecom

Meanwhile, Eric Xu, Rotating chief executive officer, Huawei, said: “Huawei is committed to socio-economic and environmental sustainability. We leverage our expertise to bridge the digital divide and deliver high-quality digital connectivity for all.”

“We always honor our commitment to supporting secure and stable network operations anytime, anywhere. We contribute to low-carbon economies by helping customers and industries improve productivity and reduce energy consumption,” said Xu at the sixth Global Supplier Sustainability Conference in Shenzhen, China.

DK Photonics – www.dkphotonics.com  specializes in designing and manufacturing of high quality optical passive components mainly for telecommunication, fiber sensor and fiber laser applications,such as PLC Splitter, WDM, FWDM, CWDM, DWDM, OADM,Optical Circulator, Isolator, PM Circulator, PM Isolator, Fused Coupler, Fused WDM, Collimator, Optical Switch and Polarization Maintaining Components, Pump Combiner, High power isolator, Patch Cord and all kinds of connectors.

Fiber Optics Sensors Provide Early Warning for Landslides-DK Photonics

CASERTA, Italy, Sept. 29, 2014 — Fiber optic sensors could warn people of imminent landslides, potentially saving lives and reducing destruction.

A team at the Second University of Naples is developing sensor technology that could detect and monitor both large landslides and slow slope movements. The researchers hope to mitigate the effects of these major natural disasters, similar to the way hurricane tracking can prompt coastal evacuations.

Optical fiber sensors embedded in shallow trenches within slopes would detect small shifts in the soil, the researchers said. Landslides are always preceded by various types of pre-failure strains, they said.

While the magnitude of pre-failure strains depends on the rock or soil involved — ranging from fractured rock debris and pyroclastic flows to fine-grained soils — they are measurable. Electrical sensors have long been used for monitoring landslides, but that type of sensor can be easily damaged, the researchers said. Optical fiber is more robust, economical and sensitive.

“Distributed optical fiber sensors can act as a ‘nervous system’ of slopes by measuring the tensile strain of the soil they’re embedded within,” said professor Dr. Luigi Zeni.

The researchers are also combining several types of optical fiber sensors into a plastic tube that twists and moves under the forces of the pre-failure strains. This will allow them to monitor the movement and bending of the optical fiber remotely to determine if a landslide is imminent.

The use of fiber optic sensors “allows us to overcome some limitations of traditional inclinometers, because fiber-based ones have no moving parts and can withstand larger soil deformations,” Zeni said.

He added that such sensors can be used to cover several square kilometers and monitored continuously to pinpoint critical zones.

The team will present their research at Frontiers in Optics in Tucson, Ariz., next month.

DK Photonics – www.dkphotonics.com  specializes in designing and manufacturing of high quality optical passive components mainly for telecommunication, fiber sensor and fiber laser applications,such as PLC Splitter, WDM, FWDM, CWDM, DWDM, OADM,Optical Circulator, Isolator, PM Circulator, PM Isolator, Fused Coupler, Fused WDM, Collimator, Optical Switch and Polarization Maintaining Components, Pump Combiner, High power isolator, Patch Cord and all kinds of connectors.

Can I use single mode equipment over multimode cable and vice versa?

This is a question we get many times from our customers. Especially common is a situation, in older installations, back to the times when multimode cable was cheaper than single mode, and inside buildings, and some last mile installations were planned so, that multimode cables were laid.

Answer is not that easy, to answer simply yes or no. Let’s delve in a details.

Definitions:

• SONET – Synchronous Optical Network
• SMF – SingleMode Fiber
• MMF – MultiMode Fiber
• LED – Light Emitting Diode
• DMD – Differential Mode Delay
• Mode -

1. light rays entering the fiber at the particular angle;
2. paths of different length and transmission delays that travel through the cable.

SMF is using laser as a source for the light and therefore light beam is very concentrated. It allows higher bandwidth compared to MMF, while having greater transmission distance.

MMF is typically using LEDs for transmission of the optical signal. It is clear from the name, that it uses multiple modes of light at the same time. Entry angles differ for each mode of the light resulting in different speeds and distances that signal can travel.

Single mode vs Multimode

1. It is possible to interconnect two devices using SMF interface at one end and MMF receiver at another one. But here, many depends also on devices. Like for example ,more sophisticated routers, like Huawei, Alcatel or Cisco while supporting that at physical layer, will not support it at TA. Problem is in DMD that may occur when two different modes are directly coupled. Degradation of the bandwidth also decreases the distance supported for transmission. Also, SMF transmitter should be calibrated in a way so the SMF signal would not overdrive MMF receiver.

Solution: Using the intermediate switch with SMF and MMF interfaces that is able to convert the signals is a good alternative.

1. If you use simple devices, such as video over fiber, or media converters, then it depends, what wavelength are used for your equipment. The trick here is that as we know, single-mode fibers used in telecommunications operate at 1310 or 1550 nm and require bit (now only a little bit) more expensive laser sources, and in older equipment MMF wavelength used were 850 nm.

And if you have this kind of transceivers, then it won’t work over your single mode cable. If you have a newer generation media converters, which use 1300 nm lasers, it will most likely work.

Table 1. Most common wavelengths (non WDM, CWDM or DWDM) used in optical transmission systems.

DK Photonics – www.dkphotonics.com  specializes in designing and manufacturing of high quality optical passive components mainly for telecommunication, fiber sensor and fiber laser applications,such as PLC Splitter, WDM, FWDM, CWDM, DWDM, OADM,Optical Circulator, Isolator, PM Circulator, PM Isolator, Fused Coupler, Fused WDM, Collimator, Optical Switch and Polarization Maintaining Components, Pump Combiner, High power isolator, Patch Cord and all kinds of connectors.

Fiber Optic Connector Market Forecast-DK Photonics

According to ElectroniCast, multifiber / multichannel fiber optic connectors are set for explosive growth, led by MXC™ fiber connectors with triple-digit increases through 2018…

Aptos, CA (USA) – September 22, 2014 --ElectroniCast Consultants, a leading market & technology forecast consultancy addressing the fiber optics communications industry, today announced the release of their annual market forecast and analysis of the use offiber optic connectors and mechanical splices in communication applications. 

According to ElectroniCast, the worldwide fiber optic connector/mechanical splice consumption value reached $2.63 billion in 2013.  Multimode fiber optic connectors led the consumption value in 2013 with a 64 percent market share.  The use of multimode fiber optic connectors is forecast to increase at a rate of 14 percent per year, from $1.68 billion in 2013 to $3.24 billion in 2018. 

“The multimode LC small form factor connector is forecast to maintain the leadership position in relative market share throughout the forecast period, as well as increasing at an average annual rate of 20 percent,” said Stephen Montgomery, Director of the Fiber Optic Component group at ElectroniCast. 

The fastest annual growth is set to come from the use of multifiber/multichannel fiber optic connectors are set for explosive growth, led by MXC™ fiber connectors with triple-digit increases through 2018.  The newly-release connector design enables more fibers (up to 64 fibers at 25G) to be accommodated in fast-paced server/storage data center and other applications.  Both the single-mode and the multimode MXC fiber optic connectors are forecast to reach strong values by 2018.  

Other new fiber optic connector designs, besides the MXC connector, are planned for deployment to address the high-density/high-speed data speeds of 25Gbps or greater in the next couple of years.

“Field-installable connectors for indoor and outdoor use are increasing in demand and thus are making a big-splash in the overall connector product lines of several competitors.  Fiber optic connector-types, such as SC, ST, LC, FC and even the MPO and other possibilities are finding their way to the marketplace.  Both mechanical-splice and fusion-splice technologies are meeting the requirements in the field-installable fiber optic product availability,” Montgomery added.

The global fiber optic connector/mechanical splice consumption is driven by a dramatic increase in bandwidth demand beyond the limits of copper.  As optical fiber use migrates closer and closer to the end user, where cable lengths are shorter with higher fiber counts, the requirements for jointing fibers becomes more critical. Splicing and connecting, play a significant role in a network’s cost and performance.

There are over 140 vendors competing for the global fiber optic connector/ mechanical splice market, which ElectroniCast tracks in a product matrix showing participation in the following: connectors, cable assemblies, optical backplanes, and fiber optic installation apparatus; however, is dominated by a few companies that have a broad base in various interconnect products. 

DK Photonics – www.dkphotonics.com specializes in designing and manufacturing of high quality optical passive components mainly for telecommunication, fiber sensor and fiber laser applications,such as WDM, FWDM, CWDM, DWDM, OADM,Optical Circulator, Isolator, PM Circulator, PM Isolator, Fused Coupler, Fused WDM, Collimator, Optical Switch and Polarization Maintaining Components, Pump Combiner, High power isolator, Patch Cord and all kinds of connectors.

Differences Between FBT Coupler and PLC splitters

Optical networks require signal being splitted somewhere in design to serve for multiple customers. Splitter technology has made a huge step forward in the past few years by introducing PLC (Planar Lightwave Circuit) splitter. It has proven itself as a higher reliable type of device compared to the traditional FBT (Fused Biconical Taper) splitter. While being similar in size and outer appearance, both types of splitters provide data and video access for business and private customers. However, internally the technologies behind these types vary, thus giving  service providers a possibility to choose a more appropriate solution.

FBT splitter is made out of materials that are easily available, for example steel, fiber, hot dorm and others. All of these materials are low-price, which determines the low cost of the device itself. The technology of the device manufacturing is relatively simple, which has the impact on its price as well. In scenario where multiple splits are needed, the size of the device may become an issue. It is important to keep in mind that splitters are being deployed in the fields either in cabinets or in strand mountings, so the size of device plays a critical role. FBT splitters only support three wavelengths (850/1310/1550 nm) which makes these devices unable to operate on other wavelengths. Inability of adjusting wavelengths makes FBT splitters less customizable for different purposes. Moreover, the devices are to a high extent temperature sensitive, providing a stable working range of -5 to 75 C. In certain areas, such as Scandinavian countries this temperature restrictions may be crucial. The signal processed by FBT splitters cannot be splitted evenly due to lack of management of the signals

PLC splitter manufacturing technology is more complex. It uses semiconductor technology (lithography, etching, developer technology) production, hence it is more difficult to manufacture. Therefore, the price of the device is higher. However, there is a number of advantages the device possesses. The size of the device is compact, compared to FBT splitters, making it suitable for density applications. PLC splitter operates at wider temperature range (-40 to 85 C), allowing its deploying in the areas of extreme climate. The split ratio goes up to 64, providing a high reliability. Furthermore, the signal can be split equally due to technology implemented. A range of wavelengths (1260 – 1650 nm) is provided, so the wavelengths are adjustable. Critical points of the device that might fail are input and output, so the general risk of failure is low.

 Table 1. FBT and PLC splitter feature comparison

DK Photonics – www.dkphotonics.com  specializes in designing and manufacturing of high quality optical passive components mainly for telecommunication, fiber sensor and fiber laser applications,such as PLC Splitter, WDM, FWDM, CWDM, DWDM, OADM,Optical Circulator, Isolator, PM Circulator, PM Isolator, Fused Coupler, Fused WDM, Collimator, Optical Switch and Polarization Maintaining Components, Pump Combiner, High power isolator, Patch Cord and all kinds of connectors.

Market Forecast–MPO Connectors in 40/100GbE - DK Photonics

MPO fiber optic connectors used in North American 40/100GbE communication links are forecast to increase at a rate of 49.8% per year through 2018…

Aptos, CA (USA) – August 20, 2014 --ElectroniCast Consultants, a leading market & technology forecast consultancy addressing the fiber optics communications industry, today announced the release of their market forecast and analysis of the use of MPO fiber optic connectors in 40 gigabit Ethernet (GbE) and 100GbE Standard communication network links.  MPO is the industry acronym for “multi-fiber push on.”

“Applications such as video, virtualization, cloud computing, switching/routing and convergence are driving the need for bandwidth expansion in data centers, 4G/LTE (wireless) networks, and other deployments.  We continue on the path of gradually migrating from 1G to 10G to 40G and 100G and eventually beyond; and the MPO connector is a key component in 40/100GbE network links, ” said Stephen Montgomery, director of the fiber optics components group at ElectroniCast.

The use of MPO fiber optic connectors in North American 40GbE and 100GbE networks is expected to reach $28 million in 2014, an increase of 84% over last year (2013). The use of 40/100GbE MPO connectors in North American is forecast to increase at annual rate of 49.8% per year over the 2013-20189 timeframe covered in the ElectroniCast market forecast. Market forecast data in the market study refers to consumption (use) for a particular calendar year; therefore, this data is not cumulative data.

The market forecast is segment by the use of single-mode and multimode 12-fiber and 24-fiber MPO connectors, and further broken-out by the use of connectors in 40G and the connectors used in 100G.

According to the market study, the North American 40/100GbE MPO connector market expansion will be dominated by the 12-fiber multimode MPO connectors, increasing at an average annual growth rate of 48.5 percent during the forecast period.

DK Photonics – www.dkphotonics.com  specializes in designing and manufacturing of high quality optical passive components mainly for telecommunication, fiber sensor and fiber laser applications,such as PLC Splitter, WDM, FWDM, CWDM, DWDM, OADM,Optical Circulator, Isolator, PM Circulator, PM Isolator, Fused Coupler, Fused WDM, Collimator, Optical Switch and Polarization Maintaining Components, Pump Combiner, High power isolator, Patch Cord and all kinds of connectors.

Ovum: Optical components market to grow 8% in 2014 from $6.8 bn in 2013

The global optical components (OC) market is expected to grow 8 percent in 2014 from $6.8 billion in 2013, said Ovum.

In 2013, the OC market increased 3 percent from 2012. Ovum said main growth drivers in 2013 were data communication sales driven by large data centers, 100G coherent demand, and unexpected growth in sales of transceivers for fiber-to-the-antenna applications for 4G build-outs.

“Demand for 100G metro–optimized transmission gear will begin shipments and ramp in 2015. Multiple component vendors introduced components and pluggable optics for 100GHz DWDM in anticipation. Opportunities are also emerging in the data center for high-speed interconnects,” said Daryl Inniss, practice leader for Telecoms Components at Ovum.

In the first quarter of 2014, the optical components market declined 1 percent sequentially and grew 7 percent compared to the year-ago period.  New lower telecom prices were one of the main reasons for the marginal growth in OC on quarter-on-quarter basis.

Ovm said demand for 100G components for coherent transmission in WAN, datacom transceivers at 10 and 40G, and fiber-to-the-antenna transceivers is expected to continue. Traffic continues to increase, and high-speed optics being used in new applications are helping to drive the market forward.

The WAN OC segment, which includes components in telecom carriers’ core and metro networks, the largest segment, will grow at a compound annual growth rate (CAGR) of 11 percent to $7 billion in 2019. Demand for 100G components and modules is a big driver for growth in WAN.  Ovum expects strong demand for pluggable coherent transceivers in 2015.

Datacom will be expanding at a 16 percent CAGR to reach $4.2 billion in 2019 — led by demand for 10 and 40G components in the early years and then 100G in the later years driven by the availability of server ports supporting data rates greater than 10G.

Access — including CATV, FTTx and transceivers for the fiber-to-the-antenna application — will decline at 2 percent CAGR to $1.1 billion in 2019. The decline will be driven by the FTTx application, where volumes are nearly constant through the forecast period but price declines are projected to pull down revenues.

DK Photonics – www.dkphotonics.com  specializes in designing and manufacturing of high quality optical passive components mainly for telecommunication, fiber sensor and fiber laser applications,such as PLC Splitter, WDM, FWDM, CWDM, DWDM, OADM,Optical Circulator, Isolator, PM Circulator, PM Isolator, Fused Coupler, Fused WDM, Collimator, Optical Switch and Polarization Maintaining Components, Pump Combiner, High power isolator, Patch Cord and all kinds of connectors.

Fiber Optic Collimator Lens Assembly Global Market Forecast-DK Photonics

Fiber optic collimator lens arrays are forecast with strong value-based growth rates of more than 45% per year (2013-2018)…

Aptos, CA (USA) – May 9, 2014 --ElectroniCast Consultants, a leading market research & technology forecast consultancy addressing the fiber optics communications industry, today announced the release of a new market forecastof the global market consumption and technology trends ofcommercial (non-military) fiber optic collimating lens assemblies, which are used in optical communication applications.

The market study covers single lens assemblies, 2-12 lens arrays, and arrays with more than 12 lenses. Both of the lens array categories are forecast with strong growth rates of more than 45% per year (2013-2018).  Single lens fiber optic collimator assemblies hold the global market share lead in the selected optical communication applications covered in the ElectroniCast study.

“Collimator lenses (and lens assemblies) are used in a variety of photonic products; however this market study forecasts the use of micro-sized collimator lens assemblies, which are used specifically in optical communication components/devices. Fiber optic collimator lens assemblies serve as a key indicator of the growth of the fiber optic communication component industry,” said Stephen Montgomery, Director of the Fiber Optic Component group at the California-based consultancy.

ElectroniCast defines lens assemblies as lenses (one or more), which are attached to an optical fiber or fitted/attached into (or on) a planar waveguide/array substrates or other device(s) for the purpose of collimating light for optical fiber communication.

The global consumption of fiber optic collimator lens assemblies, which are used in commercial optical communication applications, reached $264.2 million last year in 2013 and is forecast to reach $298.4 million this year (2014), an increase of 12.9%.    The American and APAC regions are forecast to remain relatively close together in relative consumption value market share.  The Europe, Middle East and Africa regional segment (EMEA) is forecast with the fastest average annual growth rate during the forecast period.  Market forecast data in the ElectroniCast report refers to consumption (use) for a particular calendar year; therefore, this data is not cumulative data.

Fiber optic collimator lens assemblies are widely used to covert a divergent output laser beam from a fiber or waveguide into an expanding beam of parallel light; therefore, they are used in a variety of optical communication components, such as: modulators, attenuators, transmitters, pump laser modules, switches/optical cross connects, wavelength selective switches, ROADMs, isolators, circulators, expanded-beam connector assemblies, optical filter modules, DWDM, tunable filters, optical sensors, optical signal processing, integrated/hybrid packaged modules, and other active and passive components and devices.

The Asia Pacific region is currently the leader in consumption value of the fiber optic collimator lens assembly market …

Fiber Optic Collimator Lens Assemblies

Global Market Share (%), By Region (Value Basis, Estimate - 2014)

DK Photonics – www.dkphotonics.com  specializes in designing and manufacturing of high quality optical passive components mainly for telecommunication, fiber sensor and fiber laser applications,such as WDM, FWDM, CWDM, DWDM, OADM,Optical Circulator, Isolator, PM Circulator, PM Isolator, Fused Coupler, Fused WDM, Collimator, Optical Switch and Polarization Maintaining Components, Pump Combiner, High power isolator, Patch Cord and all kinds of connectors.

Optical Isolators Global Market Forecast-DK Photonics

According to ElectroniCast, optical isolator value in Telecommunications is forecast to increase 19.6% this year…

Aptos, California (USA) – April 29, 2014  --ElectroniCast Consultants, a leading market research & technology forecast consultancy addressing the fiber optics communications industry, today announced the release of a new market forecastof the global consumption of optical isolators in optical communication and specialty applications.

According to ElectroniCast, the worldwide optical isolator consumption was led by Telecommunication applications in 2013 with a 70 percent market share or $349.7 million, and is forecasted to increase 19.6 percent in value to $418.2 million this year (2014).  Market forecast data in this study report refers to consumption (use) for a particular calendar year; therefore, this data is not cumulative data.

Optical isolators are devices that allow light to be transmitted in only one direction. They are most often used to prevent any light from reflecting back down the optical fiber, as this light would enter the source and cause backscattering and feedback problems. This is especially important for high data rate transceivers and transponders, or those devices requiring long span lengths between transceiver pairs. Optical feedback degrades signal-to-noise ratio and consequently bit-error rate.

“Continuing demand for upgrading communication networks to accommodate rapidly increasing bandwidth requirements will drive the steady consumption of optical fiber links. Optical isolators are used in with high-speed transmitters that are required to transmit longer distances and/or multiple wavelength transmitters,” stated Stephen Montgomery, Director of the Fiber Optics Components group at ElectroniCast Consultants. 

Optical isolators are not widely used in Private Enterprise applications; however, worldwide use of fiber optic isolators in Cable TV controlled device deployments are forecast to grow significantly in value at an annual rate of 8.8 percent (2013-2018), as optical fiber is deployed closer to the home driven by multi-media applications.

Optical isolator units are used in a variety of Military/Aerospace applications requiring rigorous testing and harsh environment fiber optic (HEFO) certification to ensure reliability and performance.  Laser-based fiber optic technology incorporating optical isolators are used in a wide variety of air, sea, ground, and space applications.

A major user-group within the Specialty application category is Laboratory/R&D.  Optical isolators are used for noise reduction, medical imaging, pulse selection for mode locked lasers, sensing, regeneration switches, disc master, optical trapping, phase shifters, frequency modulation spectroscopy and general shuttering. The optical isolators are also used in sensing for industrial, structures and other many other communication product-oriented manufacturing/test/R&D uses. 

“During the forecast period (2013-2018), bandwidth expansion demands will push for new network links, incorporating Metro Core, Metro/Access, Long Haul, Optical Fiber Amplifiers, WDM, OADM and other system-based deployments, which incorporate optical isolators,” Montgomery added. 

The American region held the lead in terms of relative market share consumption value of optical isolators in 2013, with nearly 43.4 percent; however the American region is forecast to increase at a slower rate compared to the other regions (2013-2018). The Asia Pacific region (APAC) is forecast to increase in worldwide market share from 39.7 percent in 2013 to with 53.7 percent in 2018.  The Europe, Middle East, African region (EMEA) is forecast to remain in the third-place position, however, increase at a faster annual pace versus the American region.

According to ElectroniCast, the American Region leads optical isolator consumption value…

2013 – Optical Isolator Global Value Market Share (%),

By Region, $498 Million

Source: ElectroniCast Consultants

Optical Isolator Global Value Market Share (%)

DK Photonics – www.dkphotonics.com  specializes in designing and manufacturing of high quality optical passive components mainly for telecommunication, fiber sensor and fiber laser applications,such as PLC Splitter, WDM, FWDM, CWDM, DWDM, OADM,Optical Circulator, Isolator, PM Circulator, PM Isolator, Fused Coupler, Fused WDM, Collimator, Optical Switch and Polarization Maintaining Components, Pump Combiner, High power isolator, Patch Cord and all kinds of connectors.

What Is a Fiber-Optic Multiplexer?--DK Photonics

What Is a Fiber-Optic Multiplexer?

A fiber-optic multiplexer is a device that processes two or more light signals through a single optical fiber, in order to increase the amount of information that can be carried through a network. Light wavelengths are narrow beams that ricochet through reflective optical tubing, sometimes over long distances, to provide instantaneous electronic signal processing at the speed of light. Multiplexers work by increasing a fiber's transmission capacity using different techniques and light source technologies. When the signal arrives at its destination, a demultiplexer separates the data streams. Using a multiplexer also allows data to be sent farther, more securely, and with less electromagnetic and radio frequency interference.

16CH CWDM

Also known as a mux, the fiber-optic multiplexer saves time and cost by squeezing more information through the optical network pathway. It is possible to split signals by varying the schedule or period of each transmission. Time Division Multiplexing (TDM) combines multiple signals by rapidly alternating between them so that only one is transmitting at any given time. Statistical Time Division Multiplexing (STDM) assigns each signal a specific time slot in order to optimize bandwidth usage. Further techniques include divisions of wavelength and frequency.

Wavelength Division Multiplexing (WDM) utilizes the total available pass band of an optical fiber. It assigns individual information streams different wavelengths, or portions of the electromagnetic spectrum. Similarly, Frequency Division Multiplexing (FDM) assigns each signal a different frequency. Carrier frequencies contain the signal while unused guard frequencies provide buffering to reduce interference. This helps minimize audible and visual noise and preserves the integrity of the original signal throughout the network.

Fiber-optic multiplexer technology serves single-mode and multimode optical fibers with multichannel rack mount or standalone units. This makes mixing channels with different configurations possible for a range of interface combinations. These devices provide stronger, more reliable transmissions in areas that have a lot of electromagnetic, radio frequency, or lightning interference.

As technology improves and information needs grow to fill the capacities of existing networks, equipment such as the fiber-optic multiplexer lessens the need to upgrade the fiber-optic infrastructure itself. Multiplexers permit new configurations of transmission protocols by increasing the amount of wavelengths or frequencies of light signals. By upgrading repeaters and terminal equipment, existing network transmission capacity can expand with demand.

Used by cellular carriers, Internet service providers, public utilities, and businesses, fiber-optic multiplexer technology extends the reach and power of telecommunications technologies. Network management systems allow for system service and maintenance, and provide for security, fault management, and system configuration. With advantages like lower costs and longer life expectancies, current fiber-optical networks are aided by improvements in multiplexing technology, and may provide light speed data transmission well into the future.

DK Photonics – www.dkphotonics.com  specializes in designing and manufacturing of high quality optical passive components mainly for telecommunication, fiber sensor and fiber laser applications,such as PLC Splitter, WDM, FWDM, CWDM, DWDM, OADM,Optical Circulator, Isolator, PM Circulator, PM Isolator, Fused Coupler, Fused WDM, Collimator, Optical Switch and Polarization Maintaining Components, Pump Combiner, High power isolator, Patch Cord and all kinds of connectors.

Free Space Optics Global Market Forecast --DK Photonics

According to ElectroniCast, the worldwide value of FSO link devices in stationary non-military/aerospace applications was $33.49 million in 2013…

Aptos, CA (USA) – January 24, 2014 --ElectroniCast Consultants, a leading market research consultancy, today announced the release of a report presenting their market analysis and forecast of Free Space Optics (FSO) communication links used in non-military/aerospace applications.

The global consumption of fixed-location (stationary) Transmitter/Receiver (T/R) links (pairs) used in non-military/ aerospace Free Space Optic system equipment was $33.49 million in 2013, up 11 percent from $29.83 million in 2012.  Free Space Optic (FSO) Transmitters and Receivers (pairs) used in link equipment with a range capability of less than 500 meters or less led in relative market share in 2013 with a global consumption value of $23.06 million.

According to the Free Space Optics Global Market Forecast & Analysis (January 2014), FSO is a line-of-sight (LOS) technology that uses directed laser beams, which provide optical bandwidth Transmitters and Receivers to link voice, video, and data intelligent transfer.  A single FSO link product (from point A to point B) often may incorporate multiple transmitters along with receiver/s to ensure adequate performance, in case of interference.

Free Space Optic communication links can be installed along railroad/subway tracks, tunnels, airport terminals, parking lot/structures or other major un-obstructed right-of-way (ROW); outdoors on building rooftops (building-to-building and/or campus), exterior walls, towers, indoors (aimed out a window), or any combination; however, a direct line-of-sight and appropriate distance are required to enable a Transmitter/Receiver Link between two points (point-to-point).

FSO-based products accommodate Ethernet-based protocols, SONET/SDH, ATM, FDDI and other standard and proprietary protocols. Products can be used for metropolitan (Metro) network extension; DWDM services, access/last mile, wireless backhaul, disaster recovery (testing and communications), storage area networks (SANs) and LAN/first mile/FTTx, and an almost endless list of other solutions.

The increase in the consumption of FSO links in the America region will be attributed to not only continued upgrades and network facilitation in the United States and Canada, but partly from the accelerating economic growth of major cities in Latin America.  Other market dynamics in the American region are increases in communication links needed for growing infrastructures, such as mass transit, security systems, broadcast and telecommunications.

European inner-city urban areas typically are difficult for wire-lines, including optical fiber cable installations; therefore, this fact promotes FSO or other wireless solutions.  The APAC region has advanced communication technology deployed especially in Japan; however, other countries, such as Australia, China and India, are not as advanced in campus-wide and metropolitan optical communication deployment.

The APAC region has rapidly expanding market opportunities and therefore, our forecast shows the region with the fastest growth (2013-2019), with the region taking over the leadership position later on in the forecast period.

According to ElectroniCast, the APAC region is forecast to eventually take the lead in terms of relative market share of non-military/aerospace FSO-Links…

Non-Military/Aerospace

FSO Global Consumption Value Market Share (%), By Region

FSO Global Consumption Value Market Share

Source: ElectroniCast Consultants

DK Photonics – www.dkphotonics.com  specializes in designing and manufacturing of high quality optical passive components mainly for telecommunication, fiber sensor and fiber laser applications,such as PLC Splitter, WDM, FWDM, CWDM, DWDM, OADM,Optical Circulator, Isolator, PM Circulator, PM Isolator, Fused Coupler, Fused WDM, Collimator, Optical Switch and Polarization Maintaining Components, Pump Combiner, High power isolator, Patch Cord and all kinds of connectors.

Fiber Optic Sensors Global Market Forecast- DK Photonics

According to ElectroniCast, the combined use of Continuous Distributed and Point fiber optics sensors will reach $4.33 Billion in 2018…

Aptos, CA (USA) – February 14, 2014 --ElectroniCast Consultants, a leading market/technology forecast consultancy, today announced the release of their market forecast and analysis of the global consumption Fiber Optic Point Sensors and Continuous Distributed Fiber Optics Sensor systems.

According to ElectroniCast, the consumption value is forecast to increase at an impressive 18% per year from $1.89 billion in 2013 to $4.33 billion in 2018.  Market forecast data refers to consumption for a particular calendar year; therefore, this data is not cumulative data.

Continuous Distributed fiber optic sensor systems involve the optic fiber with the sensors embedded with the fiber.  ElectroniCast counts each Point fiber optic sensor as one unit; however, the volume of Distributed Continuous fiber optic sensors is based on a complete optical fiber line and associated other components, which are defined as a system.

The use of Distributed Continuous fiber optic sensors in the Military/Aerospace/Security application category maintains the lead in 2014, followed by the Petrochemical/ Energy sector.  The Civil Engineering/Construction sector, which includes continuous fiber sensors used in Structural Health Monitoring (SHM) as well as other concerns in buildings, bridges, tunnels, towers, and other structures, is also forecast for strong growth.  Inspection and quality control frequently constitute the largest portion of production costs for many industries.

“There is a growing need for improved measurement solutions, which offer higher precision, speed and accuracy and provide better in-process measurement of moving objects, resulting in lower costs for better products.  Relatively speaking, the Manufacturing/ Factory segment tends to favor point sensors instead of distributed fiber systems,” stated Stephen Montgomery, Director of the Fiber Optics Components group at ElectroniCast Consultants.

“The Biomedical/ Science sector is a relatively minor user of Distributed Continuous fiber optic sensors, in terms of consumption value, since the length of optical fiber is (very) short versus the other applications; therefore the average selling prices for the distributed continuous fiber optic sensor systems are low compared to the larger (longer length of optical fiber) distributed continuous fiber optic sensor systems used in other applications. The consumption value of Distributed Continuous fiber optic sensor systems is forecast to grow at 23% per year from $1.099 billion in 2013 to $3.096 billion in the year 2018,” Montgomery added.

DATA FIGURE

According to ElectroniCast, the consumption value of fiber optic sensors (continuous distributed systems + Point-types) will increase from $1.89 billion in 2013 to $4.33 billion in 2018.

Fiber Optic Sensor Global Consumption Market Forecast

Point vs. Distributed Continuous
(Value Basis, $Million)

Fiber Optic Sensor Global Consumption Market Forecast

Note: Market forecast data refers to consumption for a particular calendar year; therefore, this data is not cumulative data.

DK Photonics – www.dkphotonics.com  specializes in designing and manufacturing of high quality optical passive components mainly for telecommunication, fiber sensor and fiber laser applications,such as PLC Splitter, WDM, FWDM, CWDM, DWDM, OADM,Optical Circulator, Isolator, PM Circulator, PM Isolator, Fused Coupler, Fused WDM, Collimator, Optical Switch and Polarization Maintaining Components, Pump Combiner, High power isolator, Patch Cord and all kinds of connectors.

Fiber Media Converters in Private Datacom Market Forecast (March 2014)

Fiber Media Converters in Private DatacomMarket Forecast (March 2014)

According to ElectroniCast, the global use of fiber media converters in private datacom networks is expected to reach $1.29 billion in 2014…

Aptos, CA (USA) – March 20, 2014 --ElectroniCast Consultants, a leader in fiber optic market research, announced the release of a new market analysis of the worldwide use of fiber optic / Fiber media converters in private data communications.  A fiber media converter is a networking device that makes it possible to connect two dissimilar media types such as copper with fiber optic cabling, as well as (different) fiber-to-fiber (F2F), such as multimode to single mode optical fiber.

The worldwide value for selected fiber media converters used in private datacom networks reached $1.07 billion in 2013. The consumption value is forecast increase with strongly rising quantity growth partially offset by declining average prices.

The EMEA and the APAC regions are forecast for double-digit consumption value growth during the timeline covered in this study (2013-2018); however, the American region’s growth is forecast to “flatten” and eventually turn to negative.  The worldwide use of private datacom fiber media converters, which are specified in the ElectroniCast market study, is forecast to peak at $1.646 billion in 2017, before slipping to $1.628 billion in 2018.

“The fiber media converters researched in this market study are typically used within an existing Private Enterprise Data Centers (DCs) and Local Area Networks (LANs), as well as other non-public data communication links. They are often used to connect newer 100-Mbps, Gigabit Ethernet, 10G, or other equipment in existing networks, which are generally (copper-based) 10BASE-T, 100BASE-T, or a mixture of both,” stated Stephen Montgomery, Director of the Fiber Optics Components group at ElectroniCast Consultants.

“Several factors make the conversion from copper to optical fiber a good choice, such as – longer link lengths in campuses and industrial plants; resistance to electromagnetic and radio-frequency interference (EMI/RFI) may be necessary; and wider bandwidth capability, just to point-out a few examples,” Montgomery added.

The strong user demand for greater bandwidth and increased interconnectivity to the desktop, throughout the buildings, campuses, from LAN-to-LAN (Metropolitan Area Network - MAN) continues in 2014.

This is matched by rapidly growing demand for global broadband interconnectivity. Interactive multimedia terminals, triple play (voice, video and data), quadruple-play (adding mobility as a communications function to the network), and numerous other dynamics/ applications, continuing bring rapid access to massive databases, which increase productivity while providing rapid ROI (return on investment).

Such expanded capability, however, must often be obtained without making the current network elements obsolete. Local area network (LAN) applications illustrate this trend.  LANs are becoming larger and more complex. Reconfiguration, relocation, and extension of LANs are occurring more frequently, due to organization restructuring, advances in computer usage, and the trend toward decentralized computing.

These changes to LAN cabling represent a major ongoing operational expense and a disruption of work for many companies (enterprises). For example, adding capabilities often requires that network administrators upgrade their existing LANs to another media type: for example, copper-to-fiber, multimode-to-singlemode fiber, or even singlemode –to- different types of singlemode optical fiber (note: copper-to-copper conversion is not covered in the study). By using media converters, the network administrator can achieve these upgrades inexpensively.

According to ElectroniCast, the global use of fiber media converters in private datacom reached $1.07 billion in 2013 and is forecast to peak at $1.646 billion in 2017, before slipping to $1.628 billion in 2018.  

Private Datacom Fiber Media Converter Global Market Forecast,
(Value Basis, $ Million) – Source: ElectroniCast Consultants

Private Datacom Fiber Media Converter Global Market Forecast,

Note: Market forecast data in this study report refers to consumption (use) for a particular calendar year; therefore, this data is not cumulative data.

DK Photonics – www.dkphotonics.com  specializes in designing and manufacturing of high quality optical passive components mainly for telecommunication, fiber sensor and fiber laser applications,such as PLC Splitter, WDM, FWDM, CWDM, DWDM, OADM,Optical Circulator, Isolator, PM Circulator, PM Isolator, Fused Coupler, Fused WDM, Collimator, Optical Switch and Polarization Maintaining Components, Pump Combiner, High power isolator, Patch Cord and all kinds of connectors.

Where can WDM-PON go next? -- DK Photonics

Where can WDM-PON go next?

The current generation of commercial WDM-PON/ 100GHz DWDM systems based on reflective ONU technology is optimized for applications up to 20 km, 40 channels, and 1 Gbps per customer. Current research focuses on how to scale WDM-PON toward higher bit rates and longer reach. Forward error correction is a key technology for scaling the current generation of WDM-PON technology to higher bit rates, longer reach, tighter channel spacing, or a combination thereof. An important challenge is to package the technology in an MSA form-factor pluggable module to maintain its benefits in cost and compatibility with third-party equipment.

A typical requirement for next generation metro/access systems is to enable node consolidation. That means operators can reduce opex by closing down portions of their central offices; at the same time, this goal requires the optical signals to bridge longer distances than what is typical of the access networks of today. Thus, when routing WDM-PON / 1064nm high power isolator signals through the metro part of the network, it becomes necessary to support ring architectures as an alternative to the basic tree structure.

In a ring structure, cascaded filters may decrease the effective channel passband. Since the spectral width of the WDM-PON signal is wider than the signals from a normal DFB source, such filtering effects may affect transmission.

In a recent evaluation project, a partnership between Transmode and Deutsche Telekom Hochschule für Telekommunikation of Leipzig, Germany, achieved 140-km long reach WDM-PON transmission over a ring-based access-network architecture. The partnership investigated the effects of using WDM-PON based on ASE-seeded wavelength-locked transmitters in a ring-based network architecture with cascaded CWDM OADM nodes. Transmission at 1.25 Gbps over 140-km singlemode fiber was demonstrated using an EDFA and dispersion compensation.

The results were first published at ECOC 2013 (In de Betou, Bunge, Åhlfeldt, and Olson, "140km Long-reach WDM-PON Test for Ring-based Access Network Architecture"). This partnership has investigated what opportunities could be provided by WDM-PON technology in such network topologies by studying experimentally the influence of narrow filtering and maximum reach.

The experimental testbed (in Leipzig) was built around Transmode's TM-Series iWDM-PON system to create an optical line terminal (OLT) (see Figure 2). The OLT has a transponder line card that hosts pluggable wavelength-locked Fabry-Perot transceivers, ASE seed light sources, dual circulators for up- and downstream, and a 40-channel multiplexer based on an AWG.

To reach distances beyond 100 km, amplifiers dispersion compensation, and remote ASE seed sources were used. While an experimental field trial today, it shows that WDM-PON may well continue to evolve to support longer reach and more sophisticated network architectures in the future supporting a broader range of deployment scenarios.

DK Photonics – www.dkphotonics.com specializes in designing and manufacturing of high quality optical passive components mainly for telecommunication, fiber sensor and fiber laser applications,such as High Power Isolator,1064nm Components,PM Components,Pump Combiner,Pump Laser Protector,which using for fiber laser applications.Also have Mini-size CWDM, Optical Circulator, PM Circulator,PM Isolator, Fused Coupler,Mini Size Fused WDM.More information,please contact us.

WDM-PON technology-DK Photonics

WDM-PON provides the dedicated bandwidth of a point-to-point network and the fiber sharing inherent in PONs. The architecture is somewhat similar to that of EPON and GPON; instead of the power-splitter approach used in TDM-PON architectures, WDM-PON uses an arrayed waveguide grating (AWG) filter that separates the wavelengths for individual delivery to the subscriber ONUs (see Figure 1).

A simple, plug-and-play implementation is based on wavelength-locked or tunable lasers. Self-tuning "colorless" ONUs can be used at the subscriber sites to simplify inventory and spare-part handling. Colorless optics not only simplify operations, but also reduce deployment costs, since they don't need the expensive wavelength-stability components that traditional fixed and tunable optics require. There are multiple approaches to the colorless ONU technology.

In one approach, the wavelength of the ONU transmitter is controlled by injection of a "seed" signal into the transmitter (e.g., a wavelength-locked Fabry-Perot laser or reflective semiconductor optical amplifier). The seed signal injected into the transmitter could come from broadband ASE light sliced through the filters in the system or from a DFB laser array. In a self-seeding version of this approach, the seed light is provided by feedback of broadband light from the transmitter itself. The passive filtering of the seed light in the remote node determines the wavelength of the ONU transmitter.

In a different approach, the colorless ONU contains a singlemode optic coupler wavelength-tunable laser, which is able to tune to the appropriate wavelength that matches the remote node filter port.

Below 10-Gbps channel bit rates, the injection-seeded method provides a cost-efficient approach. As an example, a wavelength-locked Fabry-Perot transmitter can be integrated into an MSA SFP pluggable form-factor module, which enables the use of third-party CPE devices. A modified EDFA gain block in a 70×90 MSA form factor could be used to generate the broadband ASE light that's used as a seed signal in the system.

At 10-Gbps bit rates, tunable-laser technology offers an alternative to the injection-seeded approach. The tunable-laser technology developed for the metro/long-haul market has matured significantly over the past couple of years and is able to give a good cost-per-bit ratio when high capacity is needed.

If the WDM-PON system is properly designed, then it's possible to mix different transmission technologies. By following certain design rules during the installation of the WDM-PON system, it's possible to allow step-wise channel upgrades to higher bit rates when the demand arises. These design rules ensure that channel OSNR requirements will be met in the presence of reflections and that inter-channel crosstalk is avoided. The result is an open and flexible access network that can support many applications and services over the same infrastructure. WDM-PON thus becomes an optical option for the access network as and where it makes sense.

Given its ability to help service providers cope with current bandwidth demands as well as the next potential broadband access bottleneck, WDM-PON/ 100GHz DWDM Module is becoming an important technology to consider in terms of its benefits and market timing. As with any emerging technology, service providers need to consider the optimal strategy for initial deployment of WDM-PON. That includes how they could use WDM-PON for additional network applications as the technology matures and its costs come down.

WDM-PON technology

FIGURE 2. Architectural scenario explored in the collaboration between Transmode and Deutsche Telekom Hochschule für Telekommunikation.

The latest generations of WDM-PON systems are now gaining traction with operators around the globe for field deployment, lab trials, and evaluations. It's clearly the early stage of WDM-PON deployments, but progress has started and 2014 looks to be a pivotal year for the technology.

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WDM-PON is a key component in next generation access(1)

Many industry analysts believe that the increasing requirements for bandwidth scalability, quality of service, and support of the emerging traffic patterns required by video and broadcast standards will make copper networks insufficient for many high-bandwidth services in the future. Fiber availability is not universal, and the economics of new fiber deployments are often challenging; nevertheless, fiber will undoubtedly push deeper into access networks to support business services, mobile backhaul/fronthaul, multitenant buildings/fiber to the cabinet, and in some cases fiber to the home (FTTH), too. Yet today‘s fiber-based approaches, including TDM-PON/PLC Splitter and active point-to-point Ethernet, probably won't meet the likely requirements of the next generation of bandwidth-intensive traffic, either.

WDM-PON is a passive optical networking approach -- currently being developed by several companies -- that can be used to more adequately address these challenges over fiber-based networks. A WDM-PON design can be used to separate optical-network units (ONUs) into several virtual point-to-point connections over the same physical infrastructure, a feature that enables efficient use of fiber compared to point-to-point Ethernet and offers lower latency than TDM-based approaches. A notable advantage of this approach is the combination of high capacity per user, high security, and longer optical reach. WDM-PON therefore is highly suitable for applications such as mobile backhaul or business Ethernet service provision.

Thus WDM-PON is poised to become the disruptive next generation access architecture. It will enable high-speed access for businesses, mobile backhaul, and eventually FTTH. WDM-PON also will enable operators to build converged networks and consolidate existing access networks, including potentially eliminating central offices to reduce cost while boosting performance.

There are several types of WDM-PON systems under development. They all have in common the use of passive, temperature-hardened DWDM optical filters in the remote node and colorless ONUs.

Basic WDM-PON architecture

FIGURE 1. Basic WDM-PON architecture.

DK Photonics – www.dkphotonics.com specializes in designing and manufacturing of high quality optical passive components mainly for telecommunication, fiber sensor and fiber laser applications,such as High Power Isolator,1064nm Components,PM Components,Pump Combiner,Pump Laser Protector,which using for fiber laser applications.Also have Mini-size CWDM, Optical Circulator, PM Circulator,PM Isolator, Fused Coupler,Mini Size Fused WDM.More information,please contact us.

Planar Lightwave Circuit Splitters Market Forecast

Fiber-to-the-Home deployment dominates the PLC splitter marketplace…

Fiber-to-the-Home deployment dominates the PLC splitter marketplace…

Aptos, CA (USA) – February 20, 2014  -- ElectroniCast Consultants, a leading market/technology consultancy, today announced the report release of their market forecast of the global consumption of Planar Lightwave Circuit (PLC) splitters used in Fiber Optic Communication Networks.

According to the ElectroniCast market study, the consumption value of component-level (compact device) PLC splitters reached $529.6 million in 2013. PLC splitters will continue to contribute an important role in Fiber to the Home (FTTH) networks by allowing a single passive optical network (PON) interface to be shared among many subscribers.  PLC splitters are available in compact sizes; therefore, they can be used in aerial apparatus, pedestals or in-ground as well as rack mount or other module-based value-added product. Installation is simple using a variety of connector types or fusion splicing.

“The PON-based Fiber-to-the-Home network application dominates the worldwide PLC splitter consumption value in 2014,” stated Stephen Montgomery, Director of the Fiber Optics Components group at ElectroniCast Consultants.

“The American region is forecast for flat annual growth (just over 1%); however, the EMEA region is set for 7% per year and the APAC region is forecast to increase at 15% per year, for the component-level PLC splitters, during the 2013-2018 timeframe cover by the ElectroniCast study,” Montgomery added.

DK Photonics – www.dkphotonics.com  specializes in designing and manufacturing of high quality optical passive components mainly for telecommunication, fiber sensor and fiber laser applications,such as PLC Splitter, WDM, FWDM, CWDM, DWDM, OADM,Optical Circulator, Isolator, PM Circulator, PM Isolator, Fused Coupler, Fused WDM, Collimator, Optical Switch and Polarization Maintaining Components, Pump Combiner, High power isolator, Patch Cord and all kinds of connectors.