transmission of optical communication signals such as an optical fiber the optical communication signals can further include a plurality of channels that are simultaneously transmitted along the communication medium 120 for example numerous channels having discrete wavelengths can be combined onto a single optical transmission medium using wavelength division multiplexing wdm the demultiplexer 112 is a device that is capable of optically dividing input signals received on the transmission medium 120 into a plurality of channels 104 a u2013 104 f once the input channel is divided the input channels 104 a u2013 104 f are transmitted to the optical switch matrix 102 as described above the channels can travel along the transmission medium 120 on different wavelengths additionally the channels of the input signal can be combined on the transmission medium 120 according to any well known communication technique such as tdma cdma and the like any technique that allows multiple channels to be transmitted across the transmission medium 120 and separated by the demultiplexer 112 can be used without departing from the spirit and scope of the present invention the multiplexer 114 is a device that is capable of optically combining the output channels 106 a u2013 106 f received from the optical switch matrix 102 into an output signal that.