User:D Elkington/Optical Computer

An optical computer is a computer that uses photons, rather than electrons, to manipulate, store and transmit data. Optical computer technology is still in the early stages, to date no optical computers or components have progressed beyond the prototype stage. Research into optical computers generally follows one of two paths. Some projects focus on replacing current computer components with optical equivalents, resulting in an optical digital computer system processing binary data. Such projects attempt to utilise the physical properties of the photon to achieve better performance that traditional electronic components. This approach appears to offer the best short-term prospects for commercial optical computing, since optical components could be integrated into traditional computers to produce an optical/electronic hybrid. Other research projects take non-traditional approach, attempting to develop entirely new approaches to computing that are not physically possible with electronics.

Optical Components for Binary Digital Computers
The basic elements of a digital computer are: Arithmetic Logic Unit (ALU) Control Unit Memory Bus

The ALU, Control Unit and Memory of an electronic computer consist mainly of transistors, so the key to replacing these with optical components is the development of an optical equivalent Non-linear stuff here

Memory stuff, delays in latches, etc

Bus stuff - transmission in materials, free-space

Non-traditional approaches to Optical Computing
Analogue computers

Neural Networks in hardware

Holographic memory

Current Optical Computers
No purely optical computers currently exist, however optical communication links are being considered for high performance computing systems.