Photoelasticity of ammonium sulfate crystals

All the components of πim matrix of the piezo-optic coefficients of ammonium sulfate crystals are defined using the interferometric method based on the one-pass Mach-Zehnder interferometer. All components of the рin matrix of elasto-optic coefficients are calculated on the basis of the πim matrix and elastic stiffness coefficients Сmn. Ammonium sulfate crystal should be attributed to the best photoelastic crystalline materials considering the highest values of πim and рin coefficients. The highest values of the acousto-optic figure of merit M2 are also established. The value of M2 of this crystal is 1–2 orders of magnitude higher than the value of M2 of known materials suitable for acousto-optic modulation of light in the ultraviolet spectrum region.