Manifestation of optical activity at oblique incidence of light in crystals of classes $$\overline 4 $$2 m and $$\overline 4 $$

The polarization azimuths and ellipticities of the reflected and transmitted light have been calculated as functions of the angle of incidence for transparent crystals of classes \(\overline 4 \)2m and \(\overline 4 \). Analytical expressions for these parameters are obtained. It is shown that in the general case the polarization azimuths and ellipticities for a plate cut parallel to the optical axis differ for positive and negative angles of incidence of light.