THE ANISOTROPIC PHOTOREFRACTIVE EFFECT IN BULK AS2S3 GLASS INDUCED BY POLARIZED SUBGAP LASER-LIGHT

A strong, optically anisotropic, metastable photorefractive effect is observed in bulk As2S3 glass when illuminated with a subgap polarized He-Ne laser beam. When the laser beam is focused at or near the front surface of the sample, well resolved diffractive, optically anisotropic patterns appear in the transmitted beam in the course of irradiation; i.e. a novel kind of one-beam polarized self-induced holography can be recorded in this material. The microscopic mechanism of the observed effects is considered to consist of two components: a scalar (optically irreversible) component, due to the creation of randomly directed dipole moments, with a concentration similar to 6 x 10(18) cm(-3) and a vectoral (optically reversible) component, due to the reorientation of intrinsic (native) dipole moments, with a concentration similar to 3 x 10(17) cm(-3), according to the electric vector of the inducing light.