Tag Archives: WDM

Effective CWDM & DWDM Mux/Demux Solutions for WDM System

Wavelength division multiplexing (WDM) system is designed for high capacity communications. It is now frequently used as a method to merge multiple optical signals with different wavelengths onto a single fiber. There are two divisions of WDM system: coarse wavelength division multiplexing (CWDM) and dense wavelength division multiplexing (DWDM). Using WDM can enhance the effectiveness of bandwidth in fiber optic communications. The WDM Mux/Demux has a number of communication channels, and matches with a certain frequency. Wavelengths are separated to different receivers at the destination. Mux/Demux module is an important assembly using WDM technology. This article will introduce some effective CWDM and DWDM Mux/Demux solutions for WDM system.

CWDM Mux/Demux & DWDM Mux/Demux
CWDM Mux/Demux

CWDM Mux/Demux is a flexible network solution for WDM optical networks. At most 18 full-duplex wavelengths can be added over a single fiber trunk which greatly alleviates fiber exhaustion. With low insertion loss and high stability, CWDM Mux/Demux is applied to many operations, such as CATV links, WDM systems, test and measurement, metro and access networks, FTTH networks, etc. The deployment of CWDM Mux/Demux is transparent and clear. Its compact form factor enables a much easier manipulation. Only coarse wavelengths can be transmitted over the fiber which reduces the WDM system cost.

Three kinds of CWDM Mux/Demux are widely used in the application. They are 1RU 19″ rack chassis CWDM Mux/Demux, half 19″/1RU CWDM Mux/Demux and splice/pigtailed CWDM Mux/Demux. CWDM Mux/Demux in 19 inch rack mount package is often used for CWDM, EPON and CATV network. Half 19″/1RU CWDM Mux/Demux is packed in LGX box using thing film coating and non-flux metal bonding micro optics packaging. Splice/pigtailed CWDM Mux/Demux is packed in the ABS box package based on standard thin film filter (TFF) technology.

DWDM Mux/Demux

DWDM Mux/Demux conveys optical signals in a more dense wavelength. It is especially used for long distance transmission where wavelengths are highly-packed together. The maximum delivered wavelengths can reach up to 48 channels in 100GHz grid (0.8nm) and 96 channels in 50GHz grid (0.4nm). DWDM Mux/Demux uses a reliable passive WDM technology that achieves low insertion loss. And it provides a solution for adding WDM technology to any existing network device. Applications like point-to-point DWDM fiber optimization, linear add/drop DWDM fiber optimization, external optical monitoring are typically using DWDM Mux/Demux module.

Likewise, 1RU 19″ rack chassis DWDM Mux/Demux, Half 19″/1RU DWDM Mux/Demux and splice/pigtailed DWDM Mux/Demux are three divisions of DWDM Mux/Demux modules. The first type is in 19 inch rack mount package used for long-haul transmission over C-band range of wavelengths. The second one is in LGX package used for PDH, SDH/SONET, Ethernet services transmission. The last one is in ABS box package and its pigtails are labeled with wavelengths.

Effective CWDM Mux/Demux & DWDM Mux/Demux Solutions

18-CH CWDM Mux/Demux is a highly recommended 1RU rack-mount CWDM Mux/Demux that combines 18 CWDM sources on a single fiber. The insertion loss is below 4.9 dB. Moreover, it has a monitor port that enables maintenance without ceasing the operation.


40-CH DWDM Mux/Demux has 40 channels. As a DWDM Mux/Demux module with high density, low-loss and independent 1RU rack mount package, the best utilization of this device is to employ it for high density applications over long-haul transmission. It multiplexes and demultiplexes 40 DWDM wavelengths with 100 GHz in a ring or point-point network. It is a highly cost-effective DWDM Mux/Demux module.



To improve the efficiency of network transmission, WDM technology is often deployed in the devices. 18-CH CWDM Mux/Demux and 40-CH DWDM Mux/Demux are now recommended as the most cost-effective WDM solutions with expanded fiber capabilities. Hope you can choose and use them wisely.

WDM Overview

With the development of the computers, mobile phones and some other things, there is an increasing eagerness for more traffic volume of telecommunication. So WDM, with more bandwidth and faster data transmission rate, comes into being.

WDM is a technology to send multiple different wavelength lasers on a single optical fiber. As shown in the picture below, there are different signals coming from different channels. when through the multiplexer, they can be transmitted on a single fiber without obstructed by each other at a high speed. And then, when they are through the demultiplexer, they will be allocated into different channels. The multiplexer and the demultiplexer are the most important parts in WDM systems, just like transmitter and receiver. When signals are transmitted to the network medium on the fiber links, they will be amplified. And after through the network medium, the signals will still be amplified on the fiber links untill they are received by the receiver.

WDM-wavelength division multiplexing

Currently, there are two types of it in the market. CWDM, short for coarse wavelength division multiplexing, is a low-cost WDM transmission technology. Another type is DWDM, namely, dense wavelength division multiplexing. The primary difference between them is the channel spacing. The channel spacing of CWDM is wider than DWDM, so that the number of its channels on the same link could be reduced relatively. As a result, its optical interface components does not need to be precise as same as DWDM.

Now the technology of WDM is widely used in optical networks. Why can it be so widely used? The reasons is closely linked to its features. First, it has Super capacity transmission technology. The transmission capacity can be up to 300-400 Gbit/s or even larger. Second, it can save fiber resources. No matter how many SDH subsystems there are, the whole reuse system only needs a pair of optical fiber. Third, it can work with EDFA that strengthens and restores the attenuated signals in the long-distance transmission, so that it can reduce the cost. Forth, it can improve the reliability of the system. Because most WDM systems are the photoelectric devices which have high reliability. This is a guarantee for the system reliability.

As the optical communication technology progressed further, WDM will be developed in some aspects. In terms of DWDM, Something still needs to be improved such as cost, so that more customers can adopt it.