Journal of non-crystalline solids vol:222 pages:296-303
Metastable photoinduced anisotropy (PA) generated by linearly polarized sub-bandgap light is reported in Pr-doped Ge-S-I glasses, prepared by conventional chalcogenide glass melting techniques. A PA minimum is observed in Ge34.5S55.5I10 glasses. PA increases with S content in S-rich glasses. PA increases less with Ge content at constant I content in Ge-rich glasses, while addition of I at a constant S-Ge ratio in Ge-rich glasses decreases the PA. The addition of Pr to approximately 1000 ppm increases PA in Ge-rich glasses. Microscopic models for diamagnetic defect centers responsible for PA in S-rich and Ge-rich glasses are proposed. (C) 1997 Elsevier Science B.V.