PHOTOINDUCED ANISOTROPY IN CHALCOGENIDE GLASSES IN A WIDE SPECTRAL RANGE STUDIED BY REFLECTANCE DIFFERENCE SPECTROSCOPY

We present the results of an investigation of photoinduced anisotropy in films and bulk samples of chalcogenide glasses As50Se50 and Ge20As2 0S60 using reflectance difference spectroscopy. Anisotropy in a wide s pectral range (1.5-5.5 eV) can be generated and reorientated many time s by linearly polarized light. We conclude that possibility of orienta tion and reorientation with the linearly polarized light not only of d efects and scattering centers but also of the interatomic covalent bon ds is characteristic for different chalcogenide glasses. We have found that doping of a chalcogenide glass Ge20As20S60 by rare earths does n ot change the parameters and characteristics of photoinduced anisotrop y. (C) 1998 Elsevier Science B.V. All rights reserved.