Self-induced rotation of the direction of polarization of light in crystals of 422 symmetry

The possibility of observation of self-induced optical rotation of the plane of polarization in gyrotropic crystals exhibiting a strong two-photon absorption at the investigated wavelength was confirmed experimentally for the first time. The measurements were carried out on the semiconductors CdP₂ and ZnP₂ belonging to the 422 class of the tetragonal symmetry. It was found that, in accordance with earlier theories, the angle of self-induced rotation was a linear function of the intensity of laser pulses.