Wireless and Satellite Communications

Optical Communication

Optical communication, also known as optical telecommunication, is communication at a distance using light to carry information. It can be performed visually or by using electronic devices. The earliest basic forms of optical communication date back several millennia, while the earliest electrical device created to do so was the photo phone, invented in 1880.

Optical communication is any type of communication in which light is used to carry the signal to the remote end instead of electrical current. Optical communication relies on optical fibres to carry signals to their destinations. This communication was first developed in the 1970s. Fiber optics has revolutionised the telecommunication industry and played a major role in the advent of the information age. Because of its advantages over electrical transmission, optical fibres have largely replaced copper wire communications in core networks in the developed world.

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. When electronic equipment is not employed the 'receiver' is a person visually observing and interpreting a signal, which may be either simple (such as the presence of a beacon fire) or complex (such as lights using color codes or flashed in a Morse code sequence).

Modern communication relies on optical networking systems using optical fiber, optical amplifiers, lasers, switches, routers, and other related technologies. Free-space optical communication use lasers to transmit signals in space, while terrestrial forms are naturally limited by geography and weather. This article provides a basic introduction to different forms of optical communication.