Register Forgot password?


Button Text
​​Your position
Difference between WDM, CWDM, DWDM and CCWDM modules
Source: | Author:surfiber | Published time: 2020-10-01 | 2264 Views: | Share:

How to distinguish the difference between WDM, CWDM, DWDM and CCWDM modules 

WDM is wavelength division multiplex and is divided into DWDM and CWDM.

WDM can be subdivided into CWDM (Coarse Wavelength Division Multiplexing) and DWDM (Dense Wavelength Division Multiplexing). The CWDM channel spacing is 20nm, and the DWDM channel spacing is from 0.2nm to 1.2nm.

DWDM is a dense wavelength division multiplexing, densely spaced (0.4nm or 0.8nm), with a large number of channels and high technical requirements. It is mainly used on trunk lines, and local and metropolitan area networks are also widely used. The single-channel transmission rate is high and the system capacity is large.

Advantages: The DWDM optical module has a small gap and requires an additional wavelength control device. Its main advantage is that it is the most effective solution to the expansion of the line bandwidth.

CWDM is coarse wavelength division multiplexing, with a wide channel spacing (20 nm) and a small number of channels (16 channels within the channel width range of 1200 to 1700 nm). Low technical requirements, mainly used in the metropolitan area network access network. The single channel transmission rate is relatively low and the system capacity is small.


The CWDM optical module adopts CWDM technology and can combine optical signals of different wavelengths through an external wavelength division multiplexer, because transmission is performed through one optical fiber, thereby saving optical fiber resources. At the same time, the receiver needs to use a wave demultiplexer to decompose the complex light signal. In addition, CWDM optical modules can be plugged into the switch or router SFP ports.

CCWDM is a mini wavelength division multiplexer, which is a mini version of CWDM. The size of CWDM package is basically 110×80×12mm³.

In contrast, CCWDM has a much smaller package size. Adjacent channels of CCWDM use parallel beams to be cascaded in free space instead of fiber. Without the fiber used for the cascade, the size of the CCWDM package box is only 41 × 28 × 8.7 mm³, which is 10 times smaller than the standard CWDM package.


Device and process stability, can significantly improve optical performance, reduce cost, small package size, high scalability (4/8/10 or more channels), data communication network/telecom for low-cost non-cooled laser technology The internet.