Introduction to CWDM Technology

CWDM (Coarse Wavelength Division Multiplexing) is a technology which multiplexes multiple optical signals on one fiber optic strand by making use of different wavelengths, or colors, of laser light to hold different signals. CWDM technology uses ITU standard 20nm spacing within the wavelengths, from 1270nm to 1610nm.

16CH CWDM Mux Module
16CH CWDM Mux Module

CWDM In comparison with DWDM

Accordingly, they’ve got two important characteristics built into systems employing CWDM optical components which permit easier and for that reason also less expensive than in DWDM systems. CWDM is very easy in terms of network design, implementation, and operation. CWDM works together few parameters that want optimization from the user, while DWDM systems require complex calculations of balance of power per channel, which is further complicated when channels are added and removed or when it’s utilized in DWDM networks ring, particularly if systems incorporate optical amplifiers.

 

CWDM Function

CWDM modules perform two functions. First, they filter the lighting, ensuring only the desired wavelengths are used. Second, they multiplex or demultiplex multiple wavelengths, which are put on just one fiber link. The real difference is in the wavelengths, which might be used. In CWDM space, the 1310-band as well as the 1550-band are broken into smaller bands, each only 20-nm wide. Inside multiplex operation, the multiple wavelength bands are combined onto just one fiber. Within the demultiplex operation, the multiple wavelength bands are separated from one fiber.

Generally, a CWDM network takes two forms. A point-to-point system connects two locations, muxing and demuxing multiple signals for a passing fancy fiber. A loop or multi-point system connects multiple locations, typically using Add/Drop modules.

 

CWDM Modules Types

CWDM Modules utilize thin-film coating and micro optics package technology. CWDM modules consider two main configurations: CWDM Multiplexer/Demultiplexer (CWDM Demux) modules and CWDM Add/Drop Multiplexer (CWDM OADM) modules.

Mux products will include a few statistics symptoms in a only for having using a one-time fabric. Demux isolate all of the symptoms inside various terminate. Any value reaches an extra wavelength.

CWDM Mux/demux are created to multiplex multiple CWDM channels into One or two fibers. Within a hybrid configuration (mux/demux), multiple transmit and receive signals can be combined onto a single fiber. Each signal is assigned a different wavelength. At each and every end, transmit signals are muxed, while receive signals are demuxed. CWDM Mux/demux can be a flexible plug-and-play network solution, allowing carriers and enterprise companies to cheaply implement examine point or ring based WDM optical networks. CWDM Mux/demux is modular, scalable and it’s perfectly suited to transport PDH, SDH / SONET, ETHERNET services over WWDM, CWDM and DWDM in optical metro edge and access networks.

The most popular configuration of CWDM mux/demux is 2CH, 4CH, 5CH, 8CH, 9CH, 16CH and 18CH CWDM MUX/DEMUX. and also Compact CWDM module, 3 Single fiber or dual fiber connection for CWDM Mux/demux can also be found. These modules passively multiplex the optical signal outputs from 4 or higher electronics, send to them merely one optical fiber and then de-multiplex the signals into separate, distinct signals for input into technology along at the opposite end in the fiber optic link.

More information about CWDM: WDM Products

What is Cladding Power Strippers, Where is the Cladding Power Strippers use?

Cladding Power Strippers: devices which can remove light from a fiber cladding

Cladding Power Stripper
Cladding Power Stripper

Where is the Cladding Power Strippers use?

In some situations, it is necessary to remove light from the cladding of an optical fiber. Some examples:

-Sometimes, a single-mode fiber is used as a kind of mode cleaner. The wanted light is transmitted through the fiber core, and any other light, spoiling the beam quality, should be removed. In many cases, a polymer coating around the fiber cladding can serve as a Cladding Power Stripper. For that purpose, the refractive index of the coating should be slightly above that of the cladding, so that light can easily be transmitted from the cladding into the coating and then radiated into the ambient air by scattering at irregularities. (Alternatively, the coating may absorb the light.)

-In a high-power fiber amplifier made from a double-clad fiber, residual (unabsorbed) pump light (at the fiber end opposite to the pump end) may have to be removed from the pump cladding (inner cladding) in order to prevent it either from accompanying the amplified signal or from getting to the signal source. A special Cladding Power Stripper may be used for that purpose.

-When pump light is launched into a double-clad fiber (for example, from free space), some of the optical power may get into the outer cladding around the pump cladding. It may propagate in that outer cladding up to a location where the fiber has a polymer coating, and then destroy that coating via excessive heating. That problem may be avoided with a cladding stripper which attenuates light in the outer cladding, but not in the pump cladding.

Cladding Power Stripper for use in high-power fiber lasers and amplifiers need to be able to handle substantial optical powers. It needs to be ensured that these powers are absorbed in a sufficiently widespread region, and that the generated heat can be removed safely, without damaging the mode stripper or any surrounding parts.

What is Optical Circulator? What is the application of Optical Circulator?

What is Optical Circulator?

An optical circulator is a special fiber-optic component that can be used to separate optical signals that travel in opposite directions in an optical fiber, analogous to the operation of an electronic circulator. An optical circulator is a three-port device designed such that light entering any port exits from the next. This means that if light enters port 1 it is emitted from port 2, but if some of the emitted light is reflected back to the circulator, it does not come out of port 1, but instead exits from port 3.

3 port Optical Circulator
   3 port Optical Circulator
The application of Optical Circulator
The application of Optical Circulator

Fiber optic circulators are non-reciprocal optics, 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. This can only happen when the symmetry of the system is broken, for example by an external magnetic field. A Faraday rotator is another example of a non-reciprocal optical device.

 

The Configuration of optical circulator

As shown in Fig.2(a), an optical circulator typically has three input or output ports. The signal light input into the port 1 is output from the port 2. The signal light input into the port 2 is output from the port 3. The optical circulator is often used with adding an FBG at the port 2 as shown in Fig.2(b). For reference, a composition of optical circulator is shown in Fig.3.

Optical circulator Schematic of operation and application

Figure 2: Optical circulator. (a) Schematic of operation and (b) application.

Configuration of optical circulator
Configuration of optical circulator

Figure 3: Configuration of optical circulator. 1: Poparization beam splitter (PBS), 2: reflection prism, 3 and 6: Birefringence crystal, 4: Faraday rotator, 5: half-wave plate

 

The application of Optical Circulator

An optical circulator is frequently used for an optical time domain reflectometer (OTDR), an optical add-drop multiplexer (OADM) and a dense wavelength devision multiplexing (DWDM) network using an FBG, and a pulse stretcher, a pulse compressor, and a disprersion compensator using a chirped FBG. Optical Circulators can be used to achieve bi-directional transmission over a single fiber. Because of its high isolation of the input and reflected optical powers and its low insertion loss, optical circulators are widely used in advanced communication systems and fiber-optic sensor applications.

 

Read more related articles :

Optical Circulator

DWDM & CWDM Solutions

In today’s world of intensive communication needs and requirements, “fiber optic cabling” has become a very popular phrase.  In the field of telecommunications, data center connectivity and ,video transport, fiber optic cabling is highly desirable for today’s communication needs due to the enormous bandwidth availability, as well as reliability, minimal loss of data packets, low latency and increased security.  Since the physical fiber optic cabling is expensive to implement for each individual service, using a Wavelength Division Multiplexing (WDM) for expanding the capacity of the fiber to carry multiple client interfaces is a highly advisable.  WDM is a technology that combines several streams of data/storage/video or voice protocols on the same physical fiber-optic cable by using several wavelengths (frequencies) of light with each frequency carrying a different type of data. With the use of optical amplifiers and the development of the  OTN  (Optical Transport Network) layer equipped with FEC (Forward Error Corection), the distance of the fiber optical communication can reach thousands of Kilometers without the need for regeneration sites.

 

DWDM vs. CWDM

DWDM (Dense Wavelength Division Multiplexing) is a technology allowing high throughput capacity over longer distances commonly ranging between 44-88 channels/wavelengths and transferring data rates from 100Mbps up to 100Gbps per wavelength. Each wavelength can transparently carry wide range of services such as FE/1/10/40/100GBE, OTU2/OTU3/OTU4, 1/2/4/8/10/16GB FC,STM1/4/16/64, OC3/OC12/OC48/OC-192, HD/SD-SDI and CPRI.  The channel spacing of the DWDM solution is defined by the ITU.xxx (ask Omri) standard and can range from 25Ghz, 50GHz and 100GHz which is the most widely used today. Figure – 1 shows a DWDM spectral view of 88ch with 50GHz spacing.

50GHz spacing 88 DWDM channels/wavelengths

Figure -1: Spectral view of 50GHz spacing 88 DWDM channels/wavelengths

DWDM systems can provide up to 96 wavelengths (at 50GHz) of mixed service types, and can transport to distances up to 3000km by deploying amplifiers, as demonstrated in figure 2) and dispersion compensators thus increasing the fiber capacity by a factor of x100.  Due to its more precise and stabilized lasers, the DWDM technology tends to be more expensive at the sub-10G rates, but is a more appropriate solution and is dominating for 10G service rates and above providing large capacity data transport and connectivity over long distances at affordable costs. The DWDM solution today is often embedded with ROADM (Reconfigurable Optical Add Drop Multiplexer) which enables the building of flexible remotely managed infrastructure in which any wavelength can be added or dropped at any site. An example of DWDM equipment is well demonstrated by PL-1000, PL-1000GM, PL-1000GT, PL-1000RO, PL-2000 and PL-1000TN by DK Photonics Networks.

DWDM solution

Figure-2 Optical amplifier used in DWDM solution to overcome fiber attenuation and increase distance

CWDM (Coarse Wavelength Division Multiplexing) proves to be the initial entry point for many organizations due to its lower cost.  Each CWDM wavelength typically supports up to 2.5Gbps and can be expanded to 10Gbps support.  This transfer rate is sufficient to support GbE, Fast Ethernet or 1/2/4/8/10G FC, STM-1/STM-4/STM-16 / OC3/OC12/OC48, as well as other protocols.  The CWDM is limited to 16 wavelengths and is typically deployed at networks up to 80Km since optical amplifiers cannot be used due to the large spacing between channels. An example of this equipment is well demonstrated by PL-400, PL-1000E and PL-2000 by DK Photonics Networks.

It is important to note that the entire suite of DK Photonics’ equipment is designed to support both DWDM and CWDM technology by using standards based pluggable optical modules such as SFP, XFP and SFP+. The technology used is carefully calculated per project and according to customer requirements of distance, capacity, attenuation and future needs. DK Photonics also provides migration path from CWDM to DWDM enabling low entry cost and future expansion that can be viewed in the DWDM over CWDM technology page

 

WDM Installation

For designing and implementing a WDM network, there is a need to know some basic information regarding the infrastructure such as fiber type, attenuation of fiber, distance of fiber, network topology, service type, rate and connectivity. Based on this information, calculation of the optical link budget, OSNR (Optical Signal Noise Ratio) and dispersion can be performed in order to provide reliable, error free layer-1 optical solution.

DK Photonics’ WDM diversified equipment portfolio can provide either CWDM or DWDM solution for 4 wavelengths or 88 wavelengths ranging from few km to thousands of km and fit to the exact customer network needs. The network can be a point-to-point, linear add/Drop or ring Topology with passive Mux/DeMux or ROADM based infrastructure.

The WDM equipment serves as a demarcation point and is installed behind the Ethernet switch, router fiber channel SAN Fabric or SDH/SONET ADM coloring the fiber into different spectral wavelengths and multiplexing the rates fully isolated from each other over the same fiber to the remote site.  This allows transmission of multiple channels of different services and rates of data over the same fiber utilizing the fiber resources agnostically to the service type and rate.

The WDM technology can be applied to multiple applications such as connecting building service agnostic optical layer backbone,  data centers connectivity, Video broadcast, LTE fiber, cloud computing backbone, increasing existing fiber bandwidth and spectral efficiency.

Figure 3 shows the main traditional and emerging CWDM and DWDM technology applications which keep  growing along with the rise of the cloud computing and CSP (Content Service Providers) as well as Smart phones and video applications causing constant increase  to the WDM technology deployment and new capacities such as 100G.

Main CWDM and DWDM technology applications

Figure 3 – Main CWDM and DWDM technology applications

DK Photonics’ WDM products designed for easy and fast implementation take up minimal space and use least power, thus providing the highest integration level of CWDM and DWDM networks in the smallest 1U footprint, while providing high ROI. Additionally, the CWDM DWDM optical network is managed remotely with either DK Photonics’ Light Watch NMS/EMS or the imbedded web based management system as well as via any 3rd party SNMP tool.

Read more related articles :

Filter-based WDM          CWDM            Mini CWDM Module       DWDM

Fiber Optic Sensors Global Market Forecast

According to ElectroniCast, the combined use of Continuous Distributed and Point fiber optics sensors will reach $3.98 Billion in 2017…

ShenzhenSeptember 20, 2013  — 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 system links.

According to ElectroniCast, during the 2012-2017 timeline, the consumption value will grow at an impressive average annual rate of 20.3% from $1.58 billion to $3.98 billion.  Market forecast data refers to consumption (use) for a particular calendar year; therefore, this data is not cumulative data.

Monitoring and data transmission using fiber optic sensors and optical fiber in cabling is now commonplace in various applications, via intrinsic fiber optic sensors or extrinsic fiber optic sensors.  With an intrinsic sensor, one or more of the sensing/measuring quantity or physical properties (measurand) of the optical fiber passes through or inside the optical fiber and therefore experiences a change.  Extrinsic sensing takes place in a region outside of the optical fiber and the optical fiber acts as a transmission media of light to and from (linking) the sensing interface.

Fiber optic sensor technology has experienced impressive growth since ElectroniCast first started providing market and technology analysis of the subject since the early 1980s.  In fact their analysts were tracking the various advanced photonic technologies, since 1976.

DATA FIGURE

According to ElectroniCast, the consumption value of fiber optic sensors (Continuous Distributed + POINT) will grow at an impressive average annual rate of 20.3% from $1.58 billion to $3.98 billion.

Fiber Optic Sensor
Fiber Optic Sensor

DK Photonicswww.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, 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.

DK Photobics Released Compact CWDM(Mini CWDM) Module

Shenzhen,China,September 10,2013 – DK Photonics recently released ompact CWDM(Mini CWDM) Module.

DK Photonics now can offers a Mini CWDM (compact CWDM) module that provides bandwidth capacity expansion for future network growth in one of the industry’s smallest packages.The compact CWDM modules are based on free space optics technology.It is available in 4-or 8-channel configurations.It have lower overall insertion loss and better uniformity across the channels.Its compact size and unique carrier tray set it apart, making it easier to deploy in a variety of field situations.

The Compact CWDM module comes with a carrier that allows for fast and easy snap-in mounting to splice tray or closure. Key benefits: -Compact size: (L)53.8x(W)28x(H)8 mm. -Free Space Optics design: Lower overall insertion loss and better uniformity across the channels. -Simplified inventory management: The same component can be used in the head end or outside plant and as a Mux or Demux.

About DK Photonics DK Photonics has been a well-established specialized fiber optic component supplier for fiber optic telecommunication,fiber lasers and fiber sensor applications in those years. We have excellent engineering capability, a well-established manufacturing process, and a high-quality standard.DK Photonics’ promotion products including: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.

You are most welcome to contact DK Photonics(www.dkphotonics.com) to explore a wide range of promising business opportunities.

40/100GbE MPO FIBER OPTIC CONNECTOR – NORTH AMERICA MARKET FORECAST

According to ElectroniCast, 12-fiber single mode MPO connector consumption value will increase 141% per year through 2016…

ElectroniCast Consultants, a leading market research & technology forecast consultancy addressing the fiber optics communications industry, today announced the release of their annual market forecast of the North American consumption of MPO Fiber Optic Connectors used in 40 and 100GbE communication links.

In 2006, the IEEE 802.3 working group formed the Higher Speed Study Group (HSSG) and found that the growth in bandwidth for network aggregation applications was outpacing the capabilities of networks employing link aggregation with 10 Gigabit Ethernet. (The standard was announced in July 2007 and was ratified on June 17, 2010).

Applications such as video, virtualization (cloud computing), switching/routing and convergence are driving the need for bandwidth expansion. We continue on the path of gradually developing of growth (and change) from 1G to 10G to 40G and 100G. For data center (DC) environments operating at 40GbE or 100GbE, fiber optic cabling is generally recommended because its reach supports a wider range of deployment configurations compared to copper solutions.

The capability to choose increased speed will enable networks to play with the 10GbE resources to the access layer allowing 40/100GbE to handle traffic at the aggregation and core layers.  In this market research report, ElectroniCast Consultants provides their 2011-2016 forecast and analysis of MPO fiber optic connectors used in North American 40/100GbE optical communication networks.

The 10GbE movement into the data centers will continue; however, “future-proofing” is continuing with an accent (40/100G), which is driven by significant broadband expansion demands, especially in regards to network productivity and operating expenses (OPEX costs).

According to ElectroniCast, 12-fiber multimode MPO patchcord dominate the North American (Mexico, Canada and the United States) 40/100GbE MPO connector marketplace in 2012; however, 12-fiber single mode MPO connector consumption value will increase at the fastest pace of 141% per year through 2016.

According to ElectroniCast, 12-fiber multimode MPO connectors currently dominate the North American 40/100GbE MPO connector marketplace, based on consumption value… 

40 and 100 GbE MPO Connector Value

North America Market Share (%) in 2012, by Type

                      mpo patchcord                          
(Source: ElectroniCast Consultants)

DK Photonicswww.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, 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.

The Ion exchange process and the Glass choice of the PLC Splitter Chip

Along with development of the optical communication, its good environmental stability and compatibility with fiber, began to widely used optical communication components manufacturing.( Such as self-focusing lens, optical divider, optical amplifier, etc), And extend to the sensing area, (such as: all kinds of biological and chemical sensors , current sensors which is based on fading light waves, etc.)plc splitter

Glass ion-exchange technology has several one hundred years long history, Its earliest used to change the light absorption characteristics of glass, glass coloring,then, the technology is widely used in processing on the surface of the glass surface (such as touch screen add hard processing). Along with development of the optical communication, its good environmental stability and compatibility with fiber, began to widely used optical communication components manufacturing.( Such as self-focusing lens, optical divider, optical amplifier, etc), And extend to the sensing area, (such as: all kinds of biological and chemical sensors , current sensors which is based on fading light waves, etc.)

Current mainstream technology of PLC Splitter chip includes: PECVD technology, flame hydrolysis technology, glass ion exchange technology. Glass principle and technological process of ion exchange technology as shown in figure 1,figure 2. The main process flow flame hydrolysis technology shown in figure 3. The process characteristics of contrast see table 1. From years of use and reliability experiment, the two technologies are used in mass production and the performance is good.The features of PECVD/flame hydrolysis technique are that equipment and raw materials is the existing material, but its process is very complicated, the production cycle is long, the processing tolerance is small; Glass ion exchange technology is characterized by equipment and raw materials need special customized, but its technology is relatively simple, high production efficiency, process tolerance is larger, the chip cost is relatively low.

DK Photonicswww.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.

Planar Lightwave Circuit (PLC) Splitters Market Forecast

Telecommunication applications dominate the worldwide PLC splitter marketplace…

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.

This ElectroniCast study report details of last year’s consumption and forecasts to the year 2017 of PLC splitters by product-level (level of fabrication), in selected optical communication applications.   There are actually three (3) separate market forecasts:

According to ElectroniCast, the PON, FTTx, and Telecommunication network applications dominate the worldwide PLC splitter compact device consumption value in 2012 with 77% in relative market share; followed by the cable TV segment, the PLC splitters used in Test/Measurement applications and then Harsh Environment (Military/Aerospace, Industrial) and finally Private Enterprise Networks.

In the report, ElectroniCast provides their market data covering the following optical communication applications:

  • Passive Optical Network (PON) / FTTX / Telecommunication Networks
  • Cable TV (CATV)
  • Fiber Optic Test/Measurement
  • Private Enterprise/Data Centers/Local Area Networks (LANs)
  • Harsh Environment (Military, Industrial, Other)

In 2012, the Asia Pacific region (APAC) region leads in the consumption of PLC splitter compact devices with 68% of the worldwide value, followed by the American region and finally the EMEA region.

According to ElectroniCast, the Asia Pacific region dominates the worldwide value of PLC splitters with 68% in 2012…

PLC Splitter Component-Level Compact Devices

2012 – Global Consumption Value Market Share (%), by Region

 (Source: ElectroniCast Consultants)

 PLC

DK Photonicswww.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.

Optical Isolators Global Market Forecast

According to ElectroniCast, the Asia Pacific Region leads in the use of optical isolators…

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 Asia Pacific region (APAC), region held the lead in terms of relative market share consumption volume (quantity/number of units) of optical isolators in 2012, with 47 percent; however the Asia Pacific region (APAC), pushed along by the telecommunication category in the People’s Republic of China. The consumption of optical isolators in the APAC region is forecast to nearly triple (3x) during the 2012-2017 time frame.

Optical isolators are passive 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 isolators are used in many applications in commercial, industrial, and laboratory settings.  They are reliable devices when used in conjunction with fiber optic amplifiers, fiber optic ring lasers, fiber optic links in cable TV/multimedia applications, and high-speed/ DWDM and coherent fiber optic telecommunication communication systems, laboratory R&D, sensors, gyro-systems, test/instrumentation measurement quality assurance applications in automation of manufacturing processes and several others.

ElectroniCast estimates that the Telecommunication applications held 85% of the relative market share of the worldwide consumption volume of optical isolators in 2012.

According to ElectroniCast, 13.4 million optical isolators were used in 2012…

2012 – Optical Isolator Global Volume (Quantity) Market Share (%),

By Region, 13.4 Million Units

optical isolator

DK Photonicswww.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.