Optical and holographic properties of nano-sized As2S3 films

The theoretical background as well as the experimental results of evanescent wave holographic recording with grating periods of 3.2, 0.88 and 0.37 μm (spatial frequencies of 310 mm−1, 1140 mm−1 and 2700 mm−1) in nano-sized As2S3 films with thicknesses of 29 nm, 15 nm and 10 nm are presented. The grating recording has been performed using the interference of surface-propagating evanescent waves, created by total internal light reflection. The maximum diffraction efficiency of 5.6×10−3% has been achieved for grating period of 0.88 μm and sample thickness of 15 nm. Besides, the optical characteristics as refractive index n and extinction coefficient k of the films studied have been determined from spectrophotometric measurements in 250–650 nm wavelength region. Furthermore, drawing a connection to our previous morphological investigations, the existence of a strong relationship between microstructure, optical and holographic behavior of nano-sized As2S3 films has been revealed. On this basis the possibility of applying the evanescent – wave holography as a useful nano-tool for studying structures and different phenomena at nanometer scale has been outlined.

► We present the results of holographic recording in nano-sized thin chalcogenide films.
► The gratings are produced by the interference between two surface propagating evanescent waves or plane and evanescent wave.