A model of photoinduced anisotropy in chalcogenide glasses

An electronic model of photoinduced optical anisotropy (PA) is suggested. W ithin the framework of this model, PA is attributed to photogeneration and trapping of oriented geminate electron-hole pairs. This attribution is poss ible in a disordered material with appropriately correlated traps, illumina ted by polarized light that can generate aligned geminate pairs. Since crea tion of stable oriented geminate Fairs occurs in the dispersive transport r egime, the PA build-up can be fitted with a stretched-exponential time depe ndence. (C) 2000 Elsevier Science B.V. All rights reserved.