Photo‐Induced Bending Phenomena in GeSe ₂ Glass

Glass flake of chalcogenide glass, GeSe 2 , can be bent by sideways irradiation of linearly polarized continuous‐wave and pulsed light with a photon energy below the optical bandgap of the glass. The bending direction angle depends on the polarization azimuth. For instance, the flake bends either forward or backward relative to the direction of light propagation for linearly polarized bandgap light perpendicular or parallel to the flake axis, respectively. The presence of a reciprocity law between intensity and exposure time suggests that thermal effects are not dominant. Alternatively, the photo‐induced bending (PIB) appears to arise from the photo‐induced fluidity and the optical torque. This behavior, known as PIB, is similar to that observed in As 2 S 3 , a representative chalcogenide glass.