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What is OADM? How much do you know?

The OADM, or optical add drop multiplexer, is a aperture into and out of a distinct approach fiber. In practice, best signals canyon through the device, but some would be “dropped” by agreeable them from the line. Signals basic at that point can be “added” into the band and directed to addition destination. An OADM may be advised to be a specific blazon of optical cross-connect, broadly acclimated in amicableness analysis multiplexing systems for multiplexing and acquisition cilia optic signals. They selectively add and bead alone or sets of amicableness channels from a close amicableness analysis multiplexing (DWDM) multi-channel stream. OADMs are acclimated to bulk finer admission allotment of the bandwidth in the optical area actuality anesthetized through the in-line amplifiers with the minimum bulk of electronics.

OADMs accept acquiescent and alive modes depending on the wavelength. In acquiescent OADM, the add and bead wavelengths are anchored advanced while in activating mode, OADM can be set to any amicableness afterwards installation. Acquiescent OADM uses Filter WDM, cilia gratings, and collapsed waveguides in networks with WDM systems. Activating OADM can baddest any amicableness by accessories on appeal after alteration its concrete configuration. It is additionally beneath big-ticket and added adjustable than acquiescent OADM. Activating OADM is afar into two generations.

A archetypal OADM consists of three stages: an optical demultiplexer, an optical multiplexer, and amid them a adjustment of reconfiguring the paths amid the optical demultiplexer, the optical multiplexer and a set of ports for abacus and bottomward signals. The optical demultiplexer separates wavelengths in an ascribe cilia assimilate ports. The reconfiguration can be accomplished by a cantankerous affix console or by optical switches which absolute the wavelengths to the optical multiplexer or to bead ports. The optical multiplexer multiplexes the amicableness channels that are to abide on from demultipexer ports with those from the add ports, assimilate a distinct achievement fiber.

Physically, there are several means to apprehend an OADM. There are arrays of demultiplexer and multiplexer technologies including attenuate blur filters, cilia Bragg gratings with optical circulators, changeless amplitude annoying accessories and chip collapsed arrayed waveguide gratings. The switching or reconfiguration functions ambit from the chital cilia application console to a array of switching technologies including micro-electro automated systems (MEMS), aqueous clear and thermo-optic switches in collapsed waveguide circuits.

CWDM and DWDM OADM accommodate abstracts admission for average arrangement accessories forth a aggregate optical media arrangement path. Regardless of the arrangement topology, OADM admission credibility acquiesce architecture adaptability to acquaint to locations forth the cilia path. CWDM OADM provides the adeptness to add or bead a distinct amicableness or multi-wavelengths from a absolutely multiplexed optical signal. This permits average locations amid alien sites to admission the common, point-to-point cilia bulletin bond them. Wavelengths not dropped pass-through the OADM and accumulate on in the administration of the alien site. Additional called wavelengths can be added or alone by alternating OADMS as needed.

DK Photonics provides a wide selection of specialized OADMs for WDM system. Compact CWDM module and custom WDM solutions are also available for applications beyond the current product designs including mixed combinations of CWDM and DWDM.

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.

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.

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.

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…

Shenzhen–September 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.

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, 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.

DWDM multiplexer and CWDM mux

As the DWDM mux/demux & CWDM mux/demux goods are playing an even more and more important role inside the data transmission field, today organic beef focus on the key options that come with DWDM mux and CWDM multiplexer first.

As everybody knows, DWDM which represents Dense Wavelength Division Multiplexing was created to multiplex DWDM channels into one or two fibers. This sort of products could make the optimum usage of your existing fiber optic infrastructure in an ideal way. It puts multiple signals together and sends them simultaneously along a fiber, simply with transmissions happening at different wavelengths, and also this turns an individual fiber to the virtual equal of a handful of fibers. It is really a good and also the most reasonable solution to date that will meet our increasing desires of large data transmissions. And also by using the impressive DWDM technique, it will transmit greater than 40 connections of numerous standards, data rates or protocols more than one common fiber optic link. For the DWDM products, the DWDM mux products combine several data signals into one for transporting on the single fiber as the DWDM demux (demulitplexers) separate the signals on the opposite end. Each signal reaches a different wavelength, they cooperate with each other perfectly.

The common configuration of DWDM mux is 4, 8, 16 and 32 channels. These DWDM modules passively multiplex the optical signal outputs from 4 or maybe more electronic devices, send on them an individual optical fiber and then de-multiplex the signals into separate, distinct signals for input into electronic devices in the opposite end with the fiber optic link.

The DWDM mux products always own these following features.

1.Low insertion loss and high isolation.

2.Simple to install, requires no configuration, and disassembles easily to clean.

3.Fully transparent at all data rates and protocols.

4.Completely passive, no power required, no cooling and so on.

And for the CWDM multiplexer, the core of CWDM Module application will be the passive mux/demux unit. The most popular configuration is 4 , 8 ,16 channels. Available in 19″ Rack Mount or LGX module package. Optional wide band port for existing 1310nm or 1550nm port is available to multiplex using these CWDM Channels. As well as our CWDM Transceiver series or perhaps the wavelength converter series, the bandwidth with the fiber can be employed in the economical way. The CWDM multiplexer is always be employed to improve your fiber capacity easily and quickly.

As the very best Chinese fiber optic products supplier, DK Photonics provides lots of this sort of products which are reliable and economical. If you may well not find it on our website (what we upload is the mux & demux inside a device), you can call us to customize it to suit your needs. For standalone multiplexers, it could increase dual fiber link capacity up to 18 channels and could be combined with a lot of the CWDM GBIC, SFP, XFP, X2, XINPAK, SFP modules. It’s also super easy to make use of and install, and also have some common features because the DWDM mux. Now it’s prepared to do the job, please do not hesitate to make contact with us. Thank you for visiting contact the DK Photonics representatives for more information if you need good quality and cost-effective DWDM mux and CWDM multiplexer products.

Application of Optical Add/Drop Multiplexer CWDM/DWDM Module

What’s the CWDM/DWDM Optical Add-drop Multiplexer?

The optical add-drop multiplexers (OADM) are used in wavelength-division multiplexing systems for multiplexing and routing different channels of light into or out of a single mode fiber. This is a type of optical node, which is generally used for the construction of optical telecommunications networks. An OADM may be considered to be a specific type of cross connect cabinet.

OADM Module

A traditional OADM consists of three stages: an optical demultiplexer, and optical multiplexers, and between them a method of reconfiguring the paths between the optical demultiplexer, the optical multiplexer and a set of ports for adding and dropping signals. The optical demultiplexer separates wavelengths in an input fiber onto ports. The reconfiguration can be achieved by a fiber patch panel or by optical switches which direct the wavelengths to the optical multiplexer or to drop ports. The optical multiplexer multiplexes the wavelength channels that are to continue on from demultiplexer ports with those from the add ports, onto a single output fiber.

Principles of OADM technology

General OADM node can use four port model (Figure 1) to represent, includes three basic functions: Drop required wavelength signal, Add rumored signal to other wavelengths pass through unaffected. OADM specific network process is as follows: WDM signal coming from the line contains mangy wavelength signals into OADM’s “MainInput” side, according to business required, from many wavelength signals to selectively retrieved from the end (Drop) output desired wavelength signal, relative to the end from the Add the wavelength of the input signal to be transmitted. While the other has nothing to do with the local wavelength channels directly through the OADM, and rumored signals multiplexed together, the line output from the OADM (Main Output) Output.

OADM node technical classification

Optical drop multiplexer network technologies can be divided into two types, fixed optical drop multiplexer (Fixed OADM, FOADM) and reconfigurable optical drop multiplexer (Reconfigurable OADM, ROADM).

Fixed Optical Drop Multiplexer (FOADM)

FOADM to filter as the main component, and its function is fixed to join or retrieve certain light wavelengths. General common FOADM can be divided into three types, namely Thin Film Filter type (TFF type), Fiber Bragg Grating (FBG type) and integrated planar Arrayed Waveguide Gratings (AWG type).

* TFF FOADM using thin film between the filtering effect of the different refractive index.

* FBG FOADM use of fiber Bragg grating filtering effect, with two circulator can become FOADM.

* AWG FOADM gererally used in semiconductor fabrication processes, the integration of different refractive index material is formed on a flat substrate in a planar waveguide, when different wavelength light source is incident through the couping after the import side, due to take a different path length, while the different phase delay caused by different wavelengths and thus produce certain wavelengths in the export side to form a constructive or destructive interference, making waves in the export side, the different wavelengths will follow the design on a different channel to reach, and thus achieve FOADM function.

Reconfigurable Optical Add/Drop Multiplexer (ROADM)

ROADM can always be adjusted with the distribution network to add and drop wavelength, which reconstruct the network resource allocation, the flexibility to meet the requires of modern urban network, so a flexible ROADM features, plus optical switch substantial advantage, making the current fastest growing ROADM based optical switches based ROADM (switch based OADM). ROADM mainly be the optical switch, multiplexer and demultiplexer composed, Switch-based OADM, mainly divided into Wavelength independent switch array and wavelength selection switch.

OADM network applications

WDM ROADM optical fiber suitable for different network environments.

OADM in the metropolitan network development tendency

1. Arbitrary choice must be retrieved, adding wavelength, the wavelength can take advantage of the limited resources, the node can be retrieved with the need to do to join the adjustment of the signal wavelength, and has a remote control functions. This can provide dynamic reconfiguration of optical communications network capable ROADM will be connected to the backbone network critical devices. And FOADM is used for wavelength demand network access will be smaller parts to reduce costs. Furthermore, ROADM use to all kinds of Tunable Laser, unable Filter, or wavelength selective optical switches and other components.

2. Must be able to convert incompatible wavelength suitable for the backbone network will be transmitted wavelengths. Therefore, OADM be combined with wavelength conversioin Transponder or other functional components.

3. Must be able to compensate for the node to make acquisistion, adding such action energy loss. Therefore, OADM optical amplifiers must be combined with functional components.

4. Wavelength signals related specifications, such as: the signal to noise ratio (S/N), the energy balance between the signal wavelength, etc., are required to meet network requirements. Therefore must be combined OADM variable optical attenuators (VOA), dispersion compensation module (DCM) and other components.

Application of optical communication is still broad prospects

Once the Nortel global leader in fiber optic communications during the Internet bubble in 2000, the money in the acquisition of a large number of optical communications research and the production of small and medium enterprises, the industry has been criticized in the subsequent bankruptcy of Nortel. In fact, Nortel grasp of technology trends, the direction is right, unfortunately, Nortel too hasty, global demand for optical communication was not to such an extent.

But now the situation is very different compared with around 2000. The rapid development of mobile Internet and the widespread popularity of smart mobile terminal equipment, being a huge challenge to the global telecommunications network capacity, transmission speed. The era of “data flood peak to optical communication technology has always been known by the transmission bit of new development opportunities and a huge space. Optical communication technology not only did not fall behind, the contrary, the optical communication industry chain, from fiber optic cable system equipment, terminal equipment to optical devices, a critical period in the comprehensive technology upgrade.

The field of optical communication is a noteworthy event, the National Development and Reform Commission recently organizing the preparation of strategic emerging industries key products and services Guidance Catalogue, which in conjunction with the relevant departments, the optical communication technology and product responsibility and selected emerging industries of strategic focus products.

In fiber optics, including FTTx G.657 optical fiber, broadband long-distance high speed large capacity optical fiber transmission with G.656 optical fiber, photonic crystal fiber, rare earth doped fiber (including ytterbium doped fiber, erbium doped fiber and thulium doped fiber, etc.) the laser energy transmission fiber, and has some special properties of new optical fiber, plastic optical fiber, polymer optical fiber is fully finalists. The upgrade of the fiber optic technology, will bring the data transmission capacity, distance, quality leap.

In the field of fiber access equipment, passive optical network (PON), wavelength division multiplexer (WDM),OLT and ONU on the list. Optical transmission equipment, especially the line rate of 40 Gbit/s, 100Gbit/s large capacity (1.6Tb/s and abobe) DWDM equipment, reconfigurable optical bifurcation Multiplexer (ROADM) wavelength division multiplexing system ran cross-connect (OXC) equipment, large-capacity high-speed OTN optical transport network equipment as well as packetized enhanced OTN equipment, PTN packet transport network equipment also impressively. These products are “broadband China” works to promote a powerful weapon; both long-distance backbone network, metropolitan area network or access network even close to the user’s “last mile” of these products will come in handy.

The major products are classified as strategic emerging industries in the field of optical devices, high-speed optical components (active and passive). This is the core and foundation of the field of optical communication technology, device development, the improvement of integration, function enhancement can bring significantly reduce the cost of system equipment and provide a performance boost.

At the same time, the annual OFC / NFOEC (fiber-optic communications exhibition) will be held in late March in California. This event will showcase the latest technology and research progress of the global optical component modules, systems, networks and fiber optic products, represents a new trend of development of optical communication technology.

100G for ultra-high-speed network technology is the current OFC hot one. 2012 100G technology on a global scale backbone network level scale application of 100G optical network applications will rapidly expand with the 100G device further mature. In the same time, the industry has also increased efforts to develop the 100G optical modules, silicon photonics technology pluggable multi-source agreement 100G CFP MSA CPAK optical module has been available. Outside the backbone network, 100G MAN application is the current one of OFC discussion topic.

The rise of cloud computing brings data center construction boom, 100G technology in the data center is a popular data center for high-speed pluggable optical devices is also a hot topic. Experts believe that photonic technology has a key role to play in the large enterprise data centers, but this is only a start, the size of the new cloud computing data center such as a warehouse, with more than 100,000 servers carrying the computing and storage resources, the required network bandwidth than PB level. These data centers only optical communications technology in order to achieve VCSEL (vertical cavity surface emitting lasers) and multi-mode fiber has played an important role, and will continue to introduce new fiber optic communication technology.

Things You Should Know About Filter WDM

Wavelength-division multiplexing (WDM) is overtaking since the leading technology in point-to-point transmission links. One key method is a tunable optical filter. Important features of this type of filter include low insertion loss, narrow bandwidth, high sidelobe suppression, large dynamic range, fast tuning speed, a simple control mechanism, small size, and expense effectiveness. Filter WDM module will depend on Thin Film Filter (TFF) technology. The FWDM is extensively found in EDFA, Raman amplifiers, WDM networks and fiber optics instrumentation. The unit combines or separates light at different wavelengths in the wide wavelength range. Since FWDM series offer minimal insertion loss, low polarization dependence, high isolation and excellent environmental stability, perfect for very fast WDM network systems. It really is traditionally used in optical fiber systems:1310/1550nm, 1480/1550nm, 850/1310nm, 980/1550nm and 1310/1490/1550nm.

FWDM Main Features:

Wide Operating Wavelength Range;
Low Insertion Loss;
Ultra Flat Wide Passband;
High Channel Isolation;
High Stability and reliability;
Epoxy-free on Optical Path.
FWDM Applications:
Testing Instruments;
FTTH Tri-Play System.

WDM is a method of combining multiple signals on lasers at various infared (IR) wavelengths for transmission along fiber optic media. Each laser is modulated by an impartial pair of signals. Wavelength-sensitive filters, the IR analog of visible-light color filters, are employed on the receiving end.

WDM is comparable to frequency-division multiplexing (FDM). But rather than going on at radio frequencies (RF), WDM is done inside the IR element of the electromagnetic (EM) spectrum. Each IR channel carries several RF signals combined by using FDM or time-division multiplexing (TDM). Each multiplexed IR channel is separated, or demultiplexed, in the original signals with the destination.

The usage of WDM can multiply the effective bandwidth of an fiber optic communications system with a large factor. However its cost should be compared to the choice of utilizing multiple fibers bundled in to a cable. A fiber optic repeater device referred to as erbium amplifier plans to make WDM a cost-effective long-term treatment for the bandwidth exhaustion problem.

DK Photonics offers a wide selection of WDM/CWDM/DWDM devices, like CWDM Mux/Demux, CWDM OADM, DWDM Mux/Demux, DWDM OADM, Filter WDM and so on. DK Photonics 1310/1490/1550 WDM devices based on thin-film filter technology are design to address the precise requirements from the FTTP market. Strong coating and passive device packaging capabilities feature these WDMs with excellent optical performance, good reliability and ultra-compact size.

Something you should know about CWDM DWDM and OADM

CWDM/DWDM Mux/Demux and OADM are all fit in with Passive. CWDM and DWDM technology produce an efficient strategy to share one set of fiber strands and hang together various communications interfaces, simply by using different wavelengths of light for each channel. Thus they could expand the proportions from the network without laying more fiber. And that i want to introduce the actual basical description of CWDM Mux/Demux, DWDM Mux/Demux and OADM.

As you know, Mux (Multiplexer) products combine several data signals into one for transporting over the single fiber. Demux (Demulitplexer) separates the signals at the opposite end. Each signal are at an alternative wavelength.

CWDM Mux/Demux

The Coarse Wavelength Division Multiplexing-CWDM Mux/Demux is often a flexible plug-and-play network solution, which helps insurers and enterprise companies to affordably implement denote point or ring based WDM optical networks. CWDM Mux/demux is perfectly suitable for transport PDH, SDH / SONET, ETHERNET services over WWDM, CWDM and DWDM in optical metro edge and access networks. CWDM tools are widely used in less precision optics and lower cost, un-cooled lasers with lower maintenance requirements. Weighed against DWDM and Conventional WDM, CWDM is a bit more affordable and much less power usage of laser devices. CWDM Multiplexer Modules can be found in 4, 8 and 16 channel configurations. These modules passively multiplex the optical signal outputs from 4 excessively electronic products, send on them somebody optical fiber and de-multiplex the signals into separate, distinct signals for input into gadgets along the opposite end for your fiber optic link.

DWDM Mux/Demux

The Dense Wavelength Division Multiplexing-DWDM Mux/Demux Modules are built to multiplex multiple DWDM channels into 1 or 2 fibers. Depending on type CWDM Mux/Demux unit, with optional expansion, can transmit and receive around 4, 8, 16 or 32 connections of standards, data rates or protocols more than one single fiber optic link without disturbing the other person. DWDM MUX/DEMUX modules provides best and low-cost bandwidth upgrade on your current fiber optic communication networks.

OADM

OADM(Optical Add-Drop Multiplexer) is often a device utilized in WDM systems for multiplexing and routing different channels of fiber into or out of a single mode fiber (SMF). OADM is made to optically add/drop one or multiple CWDM/DWDM channels into one or two fibers, provides capacity to add or drop an individual wavelength or multi-wavelengths from the fully multiplexed optical signal. This enables intermediate locations between remote sites gain access to the regular, point-to-point fiber segment linking them. Wavelengths not dropped pass-through the OADM and continue on in direction of the remote site. Additional selected wavelengths can be added or came by successive OADMS if required.

What is WDM? What Is the Difference Between DWDM and CWDM Optical Technologies?

What is WDM?

In the same optical fiber at the same time can let two or more than two wavelength signal transmit and receive information through different optical channel, called wavelength division multiplex, referred to as WDM. Wavelength division multiplexing includes frequency division multiplexing and wavelength division multiplexing. Optical frequency division multiplexing (FDM) technology and optical wavelength division multiplexing (WDM) technology has no obvious difference, because the light is part of the electromagnetic wave, frequency and wavelength of light have a single correspondence. Usually also can understand so, optical frequency division multiplexing mean subdivision of optical frequency, very dense optical channel. Wavelength division multiplexing means divided frequency of light, light channel far apart, even in the optical fiber with different window.

The general application of division multiplexing wavelength is respectively using a wavelength division multiplexer and demultiplexer arranged at both ends of the optical fiber, coupling and separation of different wavelength. The main four types of WDM are fused biconical taper type, dielectric film type, FBG type and planar waveguide grating type .The main characteristic is the insertion loss and isolation. Usually, the optical link using wavelength division multiplexing equipment, increase the amount of optical link loss is called WDM insertion loss. When the wavelength transmission through the same optical fiber, the D-value between the splitter input mixed power and the output end of the fiber power is called isolation.. The following are characteristics and advantages of optical wavelength division multiplexing technical:

(1) Make full use of low loss band fiber, increase the transmission capacity of optical fiber, the physical limit of an optical fiber for transmitting information doubled to several times. At present, we only use the low loss optical fiber spectrum (1310nm-1550nm) a few, WDM can fully utilize the huge bandwidth of single-mode fiber is about 25THz, the transmission bandwidth is sufficient.

(2) There are ability to transmit two or more than two asynchronous signal in the same optical fiber ,there are compatible for digital and analog signals, has nothing to do with the data rate and modulation mode, the middle line can be removed or added channel.

(3) About the optical fiber system that has built, especially early laying optical cable that core number not much, as long as the original system power is margin, we can increase the capacity; realize the transmission of multiple one-way or two-way signals without making big changes to the original system, so it has strong flexibility.

(4) Due to the large number of reducing use amount of the fiber, it can greatly reduce the construction cost, because the fiber quantity is less, when a fault occurs, the recovery is also fast and convenient.

(5) Sharing of active optical devices, the cost of transmission of multiple signals or increase new business will reduce.

(6)The active devices in the system have been substantially reduced, which improves the reliability of the system. At present, because of the light multi carrier division multiplexing of optical transmitter, optical receiver equipment’s requirements higher, technology implementation has certain difficulty, also multiple core cable used in traditional broadcast television transmission business does not appear especially shortage, so the practical application of WDM is still not much. However, with the development of CATV integrated service development, the growing demand for network bandwidth, all kinds of selective service upgrade and network implementation economic cost considerations and so on, the characteristics and advantages of WDM in the CATV transmission system gradually emerged, showing broad application prospects, even influence the development pattern of CATV network.

What Is the Difference Between DWDM and CWDM Optical Technologies?

DWDM (dense wavelength division multiplexing) is undoubtedly the first choice technology in the field of fiber optic applications today, But the cause of high cost make many do not bounteous operators hesitating. Is there a lower cost for using the wavelength division multiplexing technology? In the face of this demand, CWDM (coarse wavelength division multiplexing) emerges as the times require.

CWDM, just as its name implies, is a dense wavelength division multiplexing next of kin, the difference between CWDM and DWDM mainly has two points: first, the CWDM carrier channel spacing is wider, therefore, light in a single fiber can reuse about 5 to 6 wavelengths, that is where the “dense” and “coarse” appellation come from; Two, CWDM modulation laser using uncooled laser, but DWDM is used in cooling laser. Cooling laser using temperature tuning, uncooled laser adopts electronic tuning. Because the range of temperature distribution is nonuniform in a very wide wavelength, so the temperature tuning is very difficult to realize, the cost is very high. CWDM avoids this problem, so it greatly reduces the cost; the whole CWDM system cost only 30% of DWDM.

CWDM provides a very high access bandwidth with a low cost, suitable for point to point, Ethernet, SONET rings and all kinds of popular network structure, especially suitable for short distance, high bandwidth, access point intensive, communication applications, such as network communication between the building or building. It is particularly worth mentioning is that CWDM with the use of PON (passive optical network).PON is a cheap, one-point to multi-point optical fiber communication mode, in combination with the CWDM, each individual wavelength channel can be used as virtual optical link of PON, Implementation of broadband data transmission between center node and multiple distributed nodes.

There are several companies are offering CWDM related products at present. However, CWDM is a product of cost and performance tradeoffs; inevitably there are some performance limitations. Industry experts point out, at present the CWDM have four following disadvantages: first, CWDM in a single fiber support multiplexing wavelength number is minor, leading to future expansion cost is high; second, multiplexing, multiplexing equipment cost should also be reduced, the device cannot be simply modified of DWDM corresponding equipment; third, CWDM does not apply to metropolitan area network, the distance between metropolitan area network nodes is short , the money that operators use in CWDM equipment expansion can be used to laying more fiber, and get better effect; fourth, CWDM has not yet formed standards.

What’s more, something about the WDM products.

(1)CWDM Mux/Demux module

CWDM Mux and CWDM Demux are designed to multiplex multiple CWDM channels into one or two fibers. The core of CWDM Module application is the passive MUX DEMUX unit. The common configuration is 1×4, 1×8, 1×16 channels. Available in 19″ Rack Mount or LGX module package. Optional wide band port is available to multiplex with CWDM Channels wavelength.

(2)DWDM Mux/Demux Modules

DWDM Mux and DWDM DeMux are designed to multiplex multiple DWDM channels into one or two fibers. The common configuration is 4, 8, 16 and 40 channels. These modules passively multiplex the optical signal outputs from 4 or more electronic devices, send them over a single optical fiber and then de-multiplex the signals into separate, distinct signals for input into electronic devices at the other end of the fiber optic link

(3)Optical Splitter– a important component in EPON network

Optical splitter in optical communication era is a component of EPON network construction, is a connection of OLT and ONU passive device.

Its function is to distribute the downlink data, and focus on the uplink data. Optical splitter has an upstream optical interface, a plurality of downlink optical interface. Optical signals from the upstream optical interface over was assigned to the downstream optical interface out all transmissions, optical signals from the downlink optical interface over being allocated to uplink optical interface out transmission only. The light intensity signal downlink optical interface of each can be same, can also be different.