Introduction of products

The CWDM are by and large in view of thin coat channel innovation which is the type of item fall under the WDM class. There arrived in a total scope of Class-8 CWDM Mux-Demux and also OADM that stands for Optical Add Drop Multiplexer units with a specific end goal to meet a wide range of necessities and system arrangements.

Likewise, it has across the board applications that require the Channel CWDM. Some of them include: Gigabit and 10G Ethernet, Fiber Channel, ATM, ESCON, in Metro total, SDH/SONET, and CATV and so forth. Presently, we should talk about the accompanying components and utilizations of Channel CWDM that settle on it an ideal decision for all. The CWDM Mux / Demux items give up to 16-channel or even 18-channel Multiplexing on a solitary fiber. Standard CWDM Mux/Demux bundle sort include: ABS box bundle, LGX pakcage and 19″ 1U rackmount.


  • The loss of insertion quality creates from the presentation of a gadget into the optical fiber is by and large lesser in CWDM than alternate gadgets; this produces short inclusion costs.
  • Channel-8 CWDM is dependably very steady and solid in the meantime. Not at all like every other sort of WDM class, the Channel CWDM has higher dependability.
  • The CWDM items are typically Epoxy free on optical way; this prompts better working and Epoxy free condition while the execution.
  • In CWDM, the channel segregation is very high. This expanded seclusion prompts better and successful outcomes.


WDM and Access Organize: As these channel sorts are the piece of WDM class, these have their best application in the WDM and also Access systems.

Line Observing: These items have their incredible use in line checking. This guarantees there is no crash on a similar line of some other range or frequency.

Cellular Application: The CWDM channel arrangements have their utilizations and applications additionally in the Cellular area, and advances as the unequaled panacea for some different parts and ventures.

Telecommunication: The broadcast communications devours Channel-8 CWDM at an incredible rate. It needs to utilize these items for the straightforward transmission of signs and utilization of the filaments for the same.

Aside from every one of the elements and applications, the capacity of CWDM is additionally to unravel the deficiency of fiber and straightforward transmission of exchange while lessening the charges of system building. This is the motivation behind why the Channel CWDM and LGX CWDM Mux and DeMux Module have a matter of extraordinary heights in the realm of fiber optics, flag transmission and multiplexing and so forth.

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.

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!

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.

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.

A WDM (Wavelength Division Multiplexing) is a system that uses a multiplexing (at the transmitter) and a demultiplexer (at the receiver) for the completion of the process and transmission of the signals.

The WDM is divided into three types (WDM, CWDM and DWDM) on the basis of wavelength difference among the three. The article discusses the main differences among CWDM and DWDM.

CWDM stands for Coarse Wavelength Division Multiplexing, and DWDM is the acronym for Dense Wavelength Division Multiplexing. Whether DWDM or CWDM, both are the types of WDM mechanism and have an array of differencess.

Let’s get acquainted with the chief difference between CWDM and DWDM:

  • The Coarse WDM has less than 8 active wavelengths per optical fiber whereas the DWDM has more than 8 active wavelengths per optical fiber.
  • The CWDM has lower capacity strength and hence is low in costs; conversely the DWDM possesses high capacity –this leads to an augmented price which is worth its qualities.
  • When it comes to the difference between the distance of the two, the CWDM has short range communication because the wavelength is not amplified, and DWDM has long range communication.
  • CWDM Mux and Demux systems are developed to be used in multiplexing multiple CWDM channels into one or two fibers.
  • Another major difference is that DWDM systems are made for longer haul transmittal, by keeping the wavelengths closely packed. Also, a DWDM device can transmit more data over long distances and to a significantly larger run of cable with lesser interference than a comparable CWDM system which has a shorter haul transmittal.
  • Furthermore, the Dense Wavelength Division Multiplying systems are capable to fit more than forty different data streams in the amount akin to that of fiber used for two data streams in a CWDM system.

Apart from all the difference there is one more and that is wavelength drift is possible in CWDM, but when it comes to the DWDM –precision lasers are needed to keep channels on the target.

Beyond being different from each other –these systems play different roles in the effective transfer of the signals, and thereby both are important enough.

The world knows that the physical fiber optic cabling can be a lot expensive when it comes implementing for every service separately; but this expense can be made worthy by capacity expansion using a Wave Division Multiplexing also known as WDM.

Wave Division Multiplexing technology was evolved to expand aptitude of networks that a single fiber provides. It helps because a WDM system employs a multiplexer solution at the transmitter that combines several wavelengths in concert; also in this entire process, each carries sundry signal and at the receiver –a de-multiplexer helps in splitting them apart. Both Mux and Demux are passive and thereby require no power supply.

Types of WDM

Currently there are many kinds of standardized WDM in existence. The types / kinds of Wave Division Multiplexing are:

  • General WDM (that may include 980/1550 WDM and 1310/1550 WDM).
  • CWDM (such as CWDM Mux and Demux module and CWDM OADM module).
  • DWDM (including 50GHz, 100GHz, 200GHz DWDM mux/demux module and DWDM OADM module).

How WDM works?

The operating principle of WDM is easy and understandable. Wave Division Multiplexing is akin to the prism in the operating principle; as a prism separates white light into seven different colored rays, similarly a WDM system uses a multiplexer at the transmitter to join different signals together, and has a demultiplexer at the receiver end for splitting the signals apart. All you need is a right type of fiber optic cable, and it is possible to have a WDM device that can do both simultaneously, and can act as an optical add / drop multiplexer.

The first WDM systems (which were demonstrated with optical fiber in the early 80s) combined only two signals; however, modern systems can handle up to 160 signals. In short, WDM systems can expand the capacity of the network while accommodating many generations of technology development in optical infrastructure without having to revamp the backbone network; this quality plays in its popularity with telecommunications companies.

Communication networks are vulnerable to data congestion. This limits the end users from accessing certain links including mobile radio towers. The problem has led to management of dedicated links by a large number of wireless carriers through the optical fiber network connection.

Depending on the requirement standards the service provider is expected to comply, some even go to the extent of claiming additional dedicated strands which give access and core meshes to the mobile tower sites.  This trend depletes the number of available fiber strands denying new service providers access to mobile towers.

Thanks to the art of technology which has introduced data bottleneck solution to businesses. The compact CWDM multiplexer allows fiber capacity enhancement without the need to increase the number of fiber strands. This ensures easy communication and connectivity to mobile towers by giving quick access without bugs.


  • High channel isolation
  • Mini size
  • High insertion loss
  • Epoxy-free optical path
  • Large bandwidth


  • Mobile phone applications
  • WDM network
  • Access network
  • Tele-communication
  • Fiber optic amplifier

How it works

Compact CWDM multiplexer works by either extracting or inaugurating several signals which are broadcasted through different fiber wavelengths to efficient create more different channels. A MUX conglomerates individual light channels to the fiber at the sending end of the data link.

 On arrival, a demultiplexer (DEMUX) applies a similar optical conformation in a reverse direction, propagating via the device. The DEMUX optical filter singles out the incoming wavelengths and pairs each channel separately with fiber. This increases the number of channels transmitted through the fiber.

As the demand for more subscribers continues to grow, the CWDM scales the supply of additional bandwidth by handling bottlenecks without substantial equipment modification. According to the IEEE standards. CWDM is compact and has the capability of withstanding outside plant (OSP) environmental conditions. This allows deployment of uncooled and unheated equipment and cabinets.


Saves money

CWDM helps access network operators lower their costs by providing quality connections to their users without the need of investing on more fiber links.

High quality

Compact CWDM is designed using modern technology and complies with IEEE standards making service providers meet the global communication standards. Besides, the device has the capability of withstanding outside the plant environmental conditions giving providers favorable installation conditions.

Reduces data bugs

Networks are prone to bottlenecks. However, the device scales additional bandwidth without the need of substantial modification of the device. This ensures quick access to links despite the increase in the number of subscribers. This has enabled users to enjoy high-speed internet, telephony services, and on-demand videos without limited access.

Before making use of this new technology, access network operators must satisfy the following requirements.

  1. Bandwidth of up to 10Gps for each first-time backhaul link
  2. Facility to storing stable legacy fiber connections of between 15510nm or 1310nm
  3. Typical spans of up to 80km
  4. Uncomplicated operations which are reliable
  5. Wireless carrier segregation bandwidth
  6. Packaged and long-lasting environmental constraints for installation

There are very many passive components involved in fiber optical networks and an optical circulator is among the top options. These components help in signal delivery without any failure thus remain to be very important. When used, the optical circulator will direct the signals between different ports but maintaining a single direction. There will be no chances of the signal going in a different direction that was not intended.

Two-way situations apply

However, that does not make it a one-direction device only. There are rare situations where you can have the circulator used in a two-way situation. When there is an optical signal sent by the circulator in two different directions, the fiber is usually one. You will have the circulator fixed on the two ends of the fiber and will function by adding a signal in one end while removing from the opposite end.

Whenever you are choosing a Polarization Maintaining Optical Circulator to use, there are very many things that must be put into serious consideration. That will be the benchmark on which your choices will be based upon. Features must be one of the things that you look out for in an ideal optical circulator. The good thing is that such a circulator comes loaded with more features to make your experience remarkable.

Consider different applications

The circulator comes with two main high-power options to choose from. You can go for either 1550nm or 1064nm depending on your needs. The other standout features for Polarization Maintaining Optical Circulator include epoxy-free optical path and compact inline package. There are additional features that as well make the circulator a unique choice compared to other alternatives available.

The other thing to look at includes applications which play a key role in the functioning of an optical circulator. Main applications that you should pay attention to are bidirectional pumping, fiber sensors, add-drop multiplexing, bidirectional signal transmission systems as well as coupling inline chromatic dispersion compensation devices.

With these applications, you are sure that your circulator will give out an optimal performance. You can have a Polarization Maintaining Optical Circulator used in multiple optical settings thus it will offer you limitless options. That is because they are unidirectional and non-reciprocating while their availability as three-port makes the circulator even more suitable. Do you know that it’s possible to use optical circulators in communication systems that are more advanced? Well, that is yet another of their biggest advantage over other types of circulators.

Get optimal performance

That is made possible by the fact that optical circulators come with a very small insertion loss while their isolation levels are very high. When used in advanced systems of communication, the circulators will come as any of the common applications. The result you get from using Polarization Maintaining Optical Circulator will depend largely on how you have chosen to use it.  If you make your decision well, the result will be good but if not then you will get a different result. It will all depend on your choices.

The element of a succession of high performance products that are based on the technology called silica-on-silicon planar and an exclusive athermal packaging design demanding zero software, electrical power, or temperature control for an entirely passive DWDM solution are referred to as Athermal Arrayed Waveguide Grating Dense Wavelength Division Mux/Demultiplexer which is also known as Athermal AWG DWDM Modules.

Athermal AWG DWDM Module

This range of modular products delivers an amalgamation of high channel isolation and very low loss along with longevity as well as reliability. Each module in the range is capable of performing Mux and Demux functions. With Flat top spectral response, both band devices are easily available (including L- and C- band). Apart from this, the custom frequency grids, connectorisation options and fiber type solution are also available. These functions make the modules ideal for several applications; some of them are discussed below:

Astounding Applications of an Athermal AWG DWDM Module:

  • WDM transmission: The WDM transmission is the process of transferring WDM, (the acronym for Wavelength Division Multiplexing) which is a method of combining multiple signals onlaser beams at different IRs (infrared wavelengths) –along the fiber optic media. With 100GHz Athermal AWG DWDM Module, the WDM transmission process becomes easy and effectual.
  • WDM based ADM: As Add / Drop Multiplexing is a multiplexing function that is employed in optical technology but can also be used in electric signal transmissions by using the principle of WDM transmission.
  • Metro and long haul networks: Metro networks and also long haul networks need to use Athermal AWG DWDM Module on wide basis. These modules offer the long haul networks with the ability to mail information, post news on bulletin boards, and logon at a remote site etc.
  • Optical Signal Processing: An Optical Signal Processing, shortened to OSP is the technology (process) that enables the processing of ocular signals in a way that the data content of such signals may be modified without converting the signals into the electrical domain. This whole process too requires 100GHz Athermal AWG DWDM Module for its efficient yet effective working.

Beyond all the listed applications of Athermal AWG DWDM, there are some more, one of which is ‘Wavelength selective routing’. The AWG DWDM is an ideal choice for all the mentioned applications because of its fetching features which encompass 100GHz ITU channel spacing, Low insertion loss, high stability and reliability etc. These features make the modules effective, durable and long term reliable.