Abstract

Photorefractive materials have been used to construct optically controlled spatial light modulators (SLMs) using incoherent erasure of an index grating¹ and using photorefractive gain². An SLM should provide high resolution, large aperture, low noise and crosstalk, and fast time response. If gain is to be provided it should be high, and uniform to within the 3db criterion³. Among the currently available photorefractive materials, barium titanate has the best performance characteristics for optical signal processing applications requiring gain. It provides large index modulation, high sensitivity, reasonable response times, and crystals of good optical quality are available. However, utilization of these characteristics in a regularly cut crystal (with faces parallel to the (100), (010) and (001) crystallographic planes) introduces certain operational difficulties. To overcome these difficulties we have prepared a specially-cut crystal of BaTiO₃, with faces parallel to the (100), (011), and $\left(01\overline{1}\right)$ crystallographic planes. In this paper, we will evaluate the performance of crystals with this orientation for information processing and particularly for SLM applications.

© 1988 Optical Society of America