Time-dependent optical transmission and photoinduced anisotropic property of amorphous $As_2S_3$ thin film, deposited by vacuum evaporation and then annealed at 170℃, are investigated.
$Ar^+$ laser beam(5145A˚) is used as a pump beam for time-dependent optical transmission and weak $Ar^+$ laser beam or He-Ne laser beam (6328A˚) is used as a probe beam. Time-dependent optical transmission of $Ar^+$ probe beam is explained by thin film theory with absorption and refractive index change, and that of He-Ne probe beam, with refractive index change only. Also the changes, after pump beam off, are explained.
For the experiment of photoinduced anisotropic property, linearly polarized $Ar^+$ laser beam (30mW) is used as a pump beam and s-polarized He-Ne laser beam, as a probe beam. The polarization of $Ar^+$ laser is rotated after each experiment. The power of He-Ne laser beam, transmitted through thin film and p-polarized polarizer, is recorded. The transmitted power is increased versus time, and reach a saturation value. And the saturation value is dependent on the angle between the polarization of the pump beam and probe beam.
