Giant photoexpansion in As2S3 glass

Abstract
When illuminated with a focused beam from He‐Ne lasers, As2S3 films with thickness of ∼50 μm exhibit the thickness expansion reaching to 3 μm, which is approximately 10 times as great as that expected from the conventional photoexpansion phenomenon. The enhancement seems to be caused by photorelaxation of strain generated by photoexpansion.