Cisco offers a comprehensive portfolio of WDM transmission modules, including optical terminal filters, optical amplifiers, optical service channel, and others, to support the network applications of enterprise and service provider customers. Wavelength Division Multiplexing (WDM) is a technique that transmits multiple independent data channels over a single optical fiber, using different wavelengths (or colors) of light for each channel. This dramatically increases bandwidth capacity without increasing the number of fibers or. Everything you need to build an optical network from end-to-end.