Optical and Holographic Characteristic of As-S-Se Thin Films

The photo-induced changes in As-S-Se ternary glasses offer a possibility of using amorphous chalcogenide layers for high-density information storage, high-resolution display devices and fabrication of diffractive optical elements In this paper we report results of the photo-induced changes in the optical properties of optically uniform thin As40S60-xSex films The refractive index is determined with spectrophotometnc method in a wide spectral region. The influence of light on the dispersion parameters of thin chalcogemde films is demonstrated. The holographic properties of As40S30Se30 layers with different thickness are investigated applying a symmetrical two-beam scheme. A semiconductor laser (Lead Light Technology, Inc) generating at 532 nm is used as a light source The two beams are s-polarized The total intensity after spatial filtering and beam expanding was 10 mW/cm(2) The diffraction efficiency kinetics is monitored with a 1 5 mW semiconductor laser at 635 nm wavelength, operating at optimal reconstructed angle condition Two different gratings are recorded with grating steps 0 5 mu m and 1.5 mu m, respectively. Two film thicknesses - 0.3 mu m and 1.0 mu m are used for grating recording. The observed diffraction efficiency is not very high, but the signal - to - noise ratio is better than 200.1