CWDM Mux/Demux from T Optics</p> <div>A multiplexer (or mux) is a device that selects one of several analog or digital input signals and forwards the selected input into a single line. Multiplexers are mainly used to increase the amount of data that can be sent over the network within a certain amount of time and bandwidth.A demultiplexer (or demux) is a device that seperates the signals at the other end.Wavelength-division multiplexing (WDM) is a technology which multiplexes a number of optical carrier signals onto a single optical fiber by using different wavelengths (i.e. colours) of laser light. This technique enables bidirectional communications over one strand of fiber, as well as multiplication of capacity.