Anisotropic patterns formed in Ag–As–S ion-conducting amorphous semiconductor films by polarized light

Linearly polarized light can produce an anisotropic surface corrugation in amorphous chalcogenide films of Ag–As–S. The corrugation resembles a mouth whisker consisting of narrow fringes which are parallel to the electric field of light and streaks which radiate from the illuminated spot to directions nearly perpendicular to the electric field. Optical birefringence of about 0.01 appears with this pattern. A photo–electro–ionic interaction, which produces a form-birefringent structure, seems to be responsible for the formation process.