optical fibre

Very fine, optically-pure glass fibre through which light can be reflected to transmit images or data from one end to the other. Although expensive to produce and install, optical fibres can carry more data than traditional cables, and are less susceptible to interference. Standard optical fibre transmitters can send up to 10 billion bits of information per second by switching a laser beam on and off.

Optical fibres are increasingly being used to replace metal communications cables, the messages being encoded as digital pulses of light rather than as fluctuating electric current. Research is investigating how optical fibres could replace wiring inside computers.

Bundles of optical fibres are also used in endoscopes to inspect otherwise inaccessible parts of machines or of the living body (see endoscopy).