The WDM system uses the technology of simultaneously transmitting multiple wavelengths of optical signals in one fiber cable.Due to the different design of the communication system, the width of the interval between each wavelength is also different. According to the different channel interval, WDM can be subdivided into CWDM (coarse wavelength division multiplexing) and DWDM (dense wavelength division multiplexing). Typically, building a WDM network requires the use of a WDM multiplexer demultiplexer and a matching optical module. This article will recommend some cost-effective CWDM and DWDM multiplexer demultiplexer solutions. 

CWDM multiplexer / demultiplexer 

CWDM multiplexer demultiplexer has low insertion loss and high stability, and is suitable for many applications, such as CATV link, WDM system, metropolitan area and access network, FTTH network and so on. Because of the wide wavelength interval of CWDM system, the larger wavelength interval means that the structure of optical multiplexing demultiplexer is greatly simplified and its cost is greatly reduced. At present, there are three types of packaging CWDM multiplexer demultiplexer commonly used, they are 1 / 2 U19 "rack-type, 1 U 19" rack-type, ABS tail fiber box. 

DWDM multiplexer / demultiplexer 

The DWDM multiplexer demultiplexer is used to transmit more dense optical signals, especially for long-distance transmission with highly concentrated wavelengths. The maximum transmission wavelength can reach 48 channels in the 100GHz grid (100GHz). 96 channels can be reached in the 50GHz grid (0.4nm).The DWDM multiplexer uses reliable passive WDM technology to achieve low insertion loss, which provides a solution for adding WDM technology to any existing network device. Similarly, DWDM multiplexers have three types of packaging: 1 / 2 U19 "rack, 1 U 19" rack, ABS tail fiber box, the first for long-distance transmission of C wavelength; the second for PDH, SDH / SONET, Ethernet transmission; the last for packaging in ABS boxes. Its tail fiber is marked with wavelength. 

In order to improve the efficiency of network transmission, technology is often deployed in devices, and the products of WDM optical module are in www.grt-china.com  can find more information and solutions about the optical communications industry, welcome to visit our website.