The computing in which the information carried in the computer chips is by photons rather than electrons is called optical computing. (The light is made up of small particles called photons which have zero mass and no charge). The optical computers have microchips and other parts which primarily use light as medium of information exchange.
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 percent 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 fiber .
Importance of Optical Computing
1. With the rapid growth of computers in various applications of daily life, efforts are on to make them deliver at high speed and to make them smaller in size.
2. In this regard, the electronic computers are now reaching their saturation. They are limited not only by the speed of electrons, but also by increasing density of interconnections on microchips.
3. The solution to this problems lies with the optical computing in the long run.
Why are Optical Computers Faster?
1. The photons that travel at 3000 km/sec are the fastest medium to carry signals. The limitation produced by slow-moving electrons in electrical circuit can be solved by photons.
2. The optical data processing can perform many operations simultaneously (in parallel) much faster and easier than electronic one. The parallel processing when associated with fast switching speeds would produce staggering computational power. Bill Gates advocates that a calculation that might take 11 years for conventional computer to solve may be solved in just a single hour by optical computer.