Enhancement of the photorefractive effect by homogeneous pyroelectric fields

Abstract

Spatially uniform heating or cooling of a photorefractive strontium-barium niobate crystal yields large pyroelectric fields. Two-beam coupling measurements and observation of beam intensity profiles behind the crystal reveal that drift of charge carriers in the pyroelectric field strongly enhances the photorefractive effect. Illumination by a continuous wave laser beam causes large pyroelectric fields via absorption and heating. The drift in pyroelectric fields must be taken into account as a transport mechanism if pyroelectric crystals are used. This mechanism is promising for novel photorefractive devices.