In, wavelength-division multiplexing (WDM) is a technology which a number of signals onto a single by using different (i.e., colors) of. This technique enables communications over a single strand of fiber (also called wavelength-division duplexing) as well as multiplication of capacity.
[pdf] The basic composition of WDM systems mainly includes two types: dual-fiber unidirectional transmission and single-fiber bidirectional transmission. Unidirectional WDM involves all optical channels being transmitted in the same direction through a single optical fiber. This technique enables bidirectional communications over a. Optical multiplexing is the art of combining multiple optical signals into one to make full use of the immense bandwidth potential of an optical channel.
[pdf] 
