At the receiving end, another DWDM device separates the combined optical signals and passes each channel to an optical receiver. Only one optical fiber is used between DWDM devices (per transmission direction). How DWDM system works, and what components are needed in DWDM system?
Optical Transmitters and Receivers
Transmitters are described as DWDM components because they provide the source signals which are then multiplexed. The characteristics of optical transmitters used in DWDM systems is highly important to system design. Multiple optical transmitters are used as the light sources in a DWDM system which requires very precise wavelengths of light to operate without interchannel distortion or crosstalk. Several individual lasers are typically used to create the individual channels of a DWDM system. Each laser operates at a slightly different wavelength.
DWDM Mux/DeMux
The DWDM Mux (multiplexer) combines multiple wavelengths created by multiple transmitters and operating on different fibers. The output signal of an multiplexer is referred to as a composite signal. At the receiving end, the DeMux (demultiplexer) separates all of the individual wavelengths of the composite signal out to individual fibers. The individual fibers pass the demultiplexed wavelengths to as many optical receivers. Generally, Mux and DeMux components are contained in a single enclosure. Optical Mux/DeMux devices can be passive. Component signals are multiplexed and demultiplexed optically, not electronically, therefore no external power source is required.
