An optical communication system uses a transmitter, which encodes a message into an optical signal, a channel, which carries the signal to its destination, and a receiver, which reproduces the message from the received optical signal.OverviewOptical communication, also known as optical telecommunication, is at a distance using to. Visual techniques such as,,, and were the earliest forms of optical communication. Hydraulic telegraph semaphores date back to the 4th century BC. In the present day a variety of electronic systems optically transmit and receive information carried by pulses of light. cables are employed to carry electronic data and telephone traffic.