Piezo- and acoustooptic properties and optical activity of Sn2P2S6 crystals

Piezooptic coefficients of Sn
2
P
2
S
6
crystals are experimentally determined for and with the aid of interferometric technique. The components of the elastic stiffness tensor for these crystals are calculated on the basis of studies for the acoustic wave velocities. It is shown that estimated acoustooptic figure of merit can achieve extremely high values for Sn
2
P
2
S
6
crystals.