Optical characteristics and holographic gratings recording on As30Se70 thin films

Abstract

We have systematically studied the optical properties, the effect of laser illumination, and the effect of light induced surface deformation through direct fabrication of surface relief gratings (SRGs) on As30Se70 thin films. The transmittance, T, for as deposited and illuminated films show a red shift in the transmittance edge which associated with the decrease in energy gap and this confirms the photo-darkening effect. The variations in linear and non-linear optical parameters values have been discussed in the view of illumination effect. Giant stable surface relief gratings have been obtained by one-step holographic recording. The surface relief gratings formation in our film is investigated by atomic force microscopy (AFM). Results have been analysed in terms of available theories for these phenomena.