Light-induced bleaching and refractive index change in vitreous AsS3-GeS4 thin films

Abstract

Light-induced structural transformations (LIST) in chalcogenide glasses (ChG), discovered about 50 years ago, still remain a unique phenomenon, very large applied but not fully understood. The LIST results in variation of the optical and other properties of ChG when illuminated, which are called either photobleaching (PB) or photodarkening (PD) if the sample optical transmission at a specific wavelength increases or decreases respectively. To date, unambiguity is established that the optical effects at LIST (especially in thin films) are largely associated with glass composition, technology of preparation and post preparation thermal treatment.