Photorefractive response at high modulation depths in Bi_12TiO_20

Abstract

We present data showing a nonlinear photorefractive response at high modulation depths in a Bi12TiO20 sample when applied ac fields are used. The data are interpreted by means of both a numerical finite-difference model and an analytic theory developed by Swinburne et al. [ IEEProceedings of the International Conference on Holographic Systems, Components and Applications ( Institution of Electrical Engineers, London, 1989), p. 175]. Both models provide physical insights into the performance of semiconductor and sillenite materials with ac field enhancements.