Visible anisotropic deformation of chalcogenide glass by optical force



Semi-free As2S3 glass flakes undergo sub-mm scale anisotropic deformation upon illumination of linearly-polarized cw bandgap light. The mechanism has been ascribed to photo-induced birefringence, optical torque, and photo-induced fluidity. Quantitative measurements demonstrate that generated optical torque is ∼10–20 Nm under a light intensity of 1 mW. This value combined with measured deformation rates for As2S3 cantilevers suggests a related photo-induced fluidity of 10–1 P–1, which is much more fluidal (∼ten orders) than that reported in the conventional photo-induced fluidity. Reasons for this discrepancy are discussed. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)