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♤ An optical computer (also called a photonic computer) is a device that uses the photons in visible light or infrared (IR)beams, rather than electric current, to perform digital computations. An electric current flows at only about 10 per cent of the speed of light. This limits the rate at which data can be exchanged over long distances, and is one of the factors that led to the evolution of optical fibre. By applying some of the advantages of visible and/or IR networks at the device and component scale, a computer might someday be developed that can perform operations 10 or more times faster than a conventional electronic computer.
♤ Optical technology has made its most significant inroads in digital communications, where fibre optic data transmission has become commonplace. The ultimate goal is the so-called photonic network, which uses visible andIR energy exclusively between each source and destination. Optical technology is employed in CD-ROM drives and their relatives, laser printers, and most photocopiers and scanners. However, none of these devices are fully optical; all rely to some extent on conventional electronic circuits and components.