Investigation of anisotropy in as-evaporated amorphous chalcogenide thin films by optical waveguiding

Intrinsic birefringence in as-evaporated AsxS1−x amorphous films have been measured by means of waveguiding technique. The anisotropy is between the directions in the film plane and the perpendicular ones. Dark relaxation, annealing behavior as well as compositional dependence of the optical anisotropy in fresh amorphous films are used for analysis of the effect in terms of the microscopic model proposed. A simple phenomenological model, based on distinct structural sites in chalcogenides, is shown to qualitatively explain some aspects of this phenomenon.