CWDM can realize the multiplexing and demultiplexing between two communication channel .It can expand the capacity of single fiber to achieve bidirectional communication, which can widely used in optical network upgrade and expansion, or introduce new comprehensive business etc.

Originally, the term "coarse wavelength division multiplexing" was fairly generic, and meant a number of different things. In general, these things shared the fact that the choice of channel spacings and frequency stability was such that erbium doped fiber amplifiers (EDFAs) could not be utilized. Prior to the relatively recent ITU standardization of the term, one common meaning for coarse WDM meant two (or possibly more) signals multiplexed onto a single fiber, where one signal was in the 1550 nm band, and the other in the 1310 nm band.

CWDM is also being used in cable television networks, where different wavelengths are used for the downstream and upstream signals. In these systems, the wavelengths used are often widely separated, for example the downstream signal might be at 1310 nm while the upstream signal is at 1550nm.

An interesting and relatively recent development relating coarse WDM is the creation of GBIC and small form factor pluggable (SFP) transceivers utilizing standardized CWDM wavelengths. GBIC and SFP optics allow for something very close to a seamless upgrade in even legacy systems that support SFP interfaces. Thus, a legacy switch system can be easily "converted" to allow wavelength multiplexed transport over a fiber simply by judicious choice of transceiver wavelengths, combined with an inexpensive passive optical multiplexing device.

Passive CWDM is an implementation of CWDM that uses no electrical power. It separates the wavelengths using passive optical components such as bandpass filters and prisms. Many manufacturers are promoting passive CWDM to deploy fiber to the home.

CWDM Module- Features

·Low insertion loss
·Low PDL 
·High channel isolation
·Excellent environmental reliability

CWDM Module - Applications

·WDM system
·CATV

CWDM Module - Specifications

Note: 1. Customization is available. 
2. Insertion loss value after "/★" is "with skip filter" . 
3. Specified without connector, and add an additional 0.2dB loss per connector.

CWDM Module - Ordering Information: SUN-CWDM-A-B-C-D-E-F