In general, optical or optical technology refers to anything that relates to light or vision, whether it be visible light or infrared light that performs a specific function. For example, optical fiber, like that shown to the right is a type of wire commonly made out of glass or plastic that carries light signals. These signals can be interpreted by a computer as data (binary) and is one example of how data can be transferred over a network.
A computer mouse is another type of device that uses optical technology. It uses a light-emitting diode and photodiodes to determine the direction a mouse is moving across a surface. This then allows the computer to move the mouse cursor across the computer screen in the appropriate direction. An optical mouse works best on an opaque surface, where it can detect the direction of movement. Surfaces like glass and a mirror are not viable surfaces to use an optical device on since movement cannot be detected. Newer optical mice employ the use of a laser diode for increased resolution and movement precision.
Optical storage devices use optical technology to save and retrieve data on discs, like a Blu-ray, CD, DVD. The device uses a laser light to read information on the disc and to "write" new information to the disc for future retrieval.
Optical technology can also used in some computers, where computations are done using photons in visible or infrared beams, instead of electric current. Using this technology in a computer, called an optical computer, allows for greatly increased computational speed. Since electric current flows at one tenth the speed of light, it may someday be possible to have an optical computer that processes at ten times or more the speed of today's computer. Intel is in the process of developing better optical computing technology, which would greatly improve computer performance and reduce energy consumption. Below are some additional examples of optical terms that relate to computers.