Photoelastic and acousto-optic effects in 65GeS2-25Ga2S3-10CsCl glass

The peculiarities of photoelastic and acousto-optic effects are first tested in chalcohalide 65GeS2-25Ga2S3-10CsCl glass exploring the interferometry method. The determined piezo-optic coefficients occur to be (in Br) π11 = 2.8 ± 0.6, π12 = 6.0 ± 0.9 and π44 = − 3.2 ± 1.1. In respect to maximal acousto-optic figure of merit М2 = 55.6 · 10− 15 s3/kg proper for longitudinal acoustic wave propagation and polarization along X2 (і = 2) direction, this glass seems more perspective for photoelastic and acousto-optic modulation in visible and near IR ranges, than many alternative candidates, such as crystalline quartz, LiNbO3, CaWO4, PbMoO4, β-BaB2O4, etc. For the first time it has been shown that piezo-optic effect of isotropic solids is anisotropic, and the degree of anisotropy is the difference of π11-π12 coefficients.