Wavelength Division Multiplexer
Wavelength division multiplexing (WDM) is an optical technology that permits several wavelengths to be coupled into the same fibre cable, effectively increasing the aggregation bandwidth per fibre cable. The technology that combines a number of wavelengths into the same fibre cable is known as wavelength-division multiplexing (WDM). This chapter presents the operating principles of WDM and describes the components needed for its utilization in systems. It also presents several experiments in both multiplexing/de-multiplexing of light signals from many light sources, using different techniques. A simple way of multiplexing or de-multiplexing wavelengths can be done using a prism. WDM systems are based on the ability of a fibre cable to carry many different wavelengths without mutual interference. The output of each laser transmitter in a WDM system is set to one of the channel frequencies. Time-division multiplexing is a technique for transmitting multiple digitized data, voice, and video signals simultaneously over one fibre cable.