Sublinear photoconductivity and the photorefractive effect

Abstract

The relationship between photoconductivity and the photorefractive effect is discussed. The photoconductivity and hence the photorefractive speed in barium titanate, which are sublinear in intensity, are considered. The photorefractive speed increases as a power law with an exponent that ranges from 0.6 to 1.0; however, most of the crystals studied have photoconductivity exponents at the low end of this range. Attempts to model the sublinear intensity dependence in barium titanate are discussed.