Optical and Holographic Properties of Nano-Sized Amorphous Semiconductor Films as a Part of Optically Addressed Spatial Light Modulator

The experimental results as well as the theoretical background of evanescent wave holographic recording of gratings with 3.2, 0.88 and 0.37 mum pitch (corresponding to spatial frequencies of 310, 1140 and 2700 mm^-1) in nano-sized As₂S₃ films are presented. The thickness of the recording medium is 29 nm. The grating recording is performed using the interference of surface-propagated reference evanescent waves, created by the total internal light reflection and homogeneous object wave. The optical characteristics of the chalcogenide films -the refractive and absorption indexes are determined by spectrophotometric measurements in the wavelength range of 250-650 nm. The examinations are connected to the application of the As₂S₃ films as a photosensitive part of optically addressed spatial light modulator working in total internal reflection mode.