Optical Computing and the Role of Photorefractive Crystals

Abstract

“Optical computing” is a term which has been used to describe many types of optical systems. This article concentrates on one optical computer design which appears to be particularly promising and competitive with digital electronic systems and which can use photorefractive (PR) crystals. We begin by discussing the motivation for constructing optical and optoelectronic computing systems and go on to describe two approaches to constructing optical computers. The first does not use PR crystals as yet but serves to indicate other approaches. The second approach involves the operation of one type of optical neural network. We discuss in detail the recording of holographic memories in a PR crystal for inclusion in the optical neural network described here.