Optical computing: A field in flux: A worldwide race is on to develop machines that compute with photons instead of electrons ¿ but what is the best approach?

The growth and development of the optical computing field is reviewed. The range of aspects explored includes the best materials for electrooptic devices, the circuits that can be built from those devices, the computer architectures that can incorporate those components, and the algorithms that can be run on machines configured for light beams instead of electronic signals. The author considers hybrid computing systems which are close to achieving electronic logic and optical interconnections including reconfigurable optical interconnects. Military applications of analog optical computing are discussed. Research on the optical equivalent of the transistor is described and novel optical computing elements and architectures are considered. Work on neural physiology and psychology is noted which reveals aspects of learning and memory that may be applicable to optical computers. Current worldwide research in materials, devices, algorithms and architectures for optical computing systems is summarized. Differing approaches to research and development are reviewed and contrasted for experts, skeptics, and observers in the field.