TORSION INDUCED GYROTROPY IN HEXAGONAL CDS

The mechanically induced gyrotropy is studied in crystal plates of hex agonal CdS near the frequency of isotropic point (in which the refract ive indices of the ordinary and extraordinary waves are equal). The tr ansmittance of light by torsion deformed crystal (when the torsional m oment is orientated along the optical c-axis) between two crossed pola rizers is measured as well as the polarization parameters of elliptica lly polarized emergent light. In the discussion the hypothesis that th e mechanical deformation induces gyrotropy is argued. The experimental results are interpretated in the frameworks of the theory of the elli ptical birefringence.