Potential device applications using photorefractive materials

Abstract

Summary form only given, as follows. The author reviews device technologies that may benefit from the use of photorefractive materials. These include optical data storage, associative memory, neural networks, optical crossbars, and optical defect inspection. For these technologies, the author defines the properties desired of photorefractive materials. Photorefractive materials exhibit a broad range of properties. These properties determine the utility of the material in any particular device application. Materials with a property of special appeal to an application may be deficient in another important property. It is therefore essential to understand the properties demanded by certain applications, and to mount a research program to determine the ability to alter the properties of the base materials with which one can work. As a result of this activity, a great deal can be learned about the accuracy of the solid-state models used to project the capabilities of these materials. A research program on photorefractive materials is described that addresses such properties as retention time, diffraction efficiency, speed, and wavelength response. The effect of doping on these parameters is demonstrated, and some fundamental shortcomings in the classic band transport model are noted.