An experimental study of the holographic gratings recorded in nonannealed, thermally with time relaxed amorphous As2S3 films by 514.5-nm light in the presence of 632.8-nm readout light is carried out. The dependences of the maximal first-order diffraction efficiency on the holographic grating period was studied in a wide range of periods, from 0.40 to 70.0 μm. A peculiar oscillatory diffraction-efficiency temporal behavior occurring under certain conditions is reported. The obtained results are discussed in terms of photoinduced structural changes, relaxational structural changes, photoinduced anisotropy, and photoinduced recharging of the localized states in the bandgap. The diffraction-efficiency oscillations are explained by the model of annihilating defects and by multiwave mixing in a thin dynamic hologram.
© 1999 Optical Society of America
(050.1950) Diffraction and gratings : Diffraction gratings
(090.2900) Holography : Optical storage materials
(160.2750) Materials : Glass and other amorphous materials
(310.6860) Thin films : Thin films, optical properties
O. Nordman, A. Ozols, and N. Nordman, "Diffraction-efficiency oscillations in amorphous As2S3 films," J. Opt. Soc. Am. B 16, 631-636 (1999)