Understanding CWDM and 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). 

CWDM Mux/Demux
CWDM supports up to 18 wavelength channels transmitted through a fiber at the same time. To achieve this, the different wavelengths of each channel are 20nm apart. DWDM, supports up to 80 simultaneous wavelength channels, with each of the channels only 0.8nm apart. CWDM technology offers a convenient and cost-efficient solution for shorter distances of up to 70 kilometers. For distances between 40 and 70 kilometers, CWDM tends to be limited to supporting eight channels.

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. 



DWDM Mux/Demux
Unlike CWDM, DWDM connections can be amplified and can, therefore, be used for transmitting data much longer distances. 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.


Types of WDM available

* 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