The difference between WDM

The difference between WDM

Coarse wavelength division multiplexing (Carse wavelength division multiplexing, CWDM) is a technology that uses optical multiplexers to multiplex the wavelengths transmitted in different optical fibers into a single fiber for transmission. Its channel is more dense than wavelength division multiplexing ( Dense wavelength division multiplexing (DWDM) is less, but more than standard wavelength division multiplexing (WDM).

The interval between multiplexed wavelengths of the CWDM system is relatively wide, at 20 nm, and DWDM is 0.4 nm. Therefore, the requirements of CWDM for lasers and multiplexers / demultiplexers are greatly reduced, which greatly reduces the cost of capacity expansion. In a typical CWDM system, the laser transmitter contains eight channels with eight defined wavelengths: 1610 nanometers, 1590 nanometers, 1570 nanometers, 1550 nanometers, 1530 nanometers, 1510 nanometers, 1490 nanometers, and 1470 nanometers. Up to 18 different channels are allowed, with a wavelength range down to 1270 nanometers.