Effect of optical activity on the self-focusing of light beams in cubic photorefractive crystals

摘要

The self-focusing of Gaussian light beams and the propagation of screening spatial solutions in a cubic optically active photorefractive crystal with the (110) cut plane are studied for an arbitrary orientation of an external electric field in this plane. A change in the rotation of the polarisation plane caused by the nonlinear interaction of light with the crystal is studied theoretically. It is shown that optical activity enhances self-focusing in some cases. Screening self-focusing was observed in an incoherently illuminated Bi_(12)SiO_(20) crystal without additional laser irradiation. The experimental data well agree with the proposed theoretical model.