Self-diffraction electrogyration and electroellipticity in centrosymmetric crystals

A theoretical investigation is made of the self-diffraction of light beams in centrosymmetric crystals of the 4/m class. It is shown that formation of dynamic holographic gratings in photosensitive crystals is accompanied by a change in the polarization and by energy exchange even in the absence of an external electric field. Numerical estimates obtained for a PbMoO₄ crystal show that in the case of self-diffraction the ellipticity can change by about 4×10^–2 and the energy exchange by 11 % in crystals 1 cm thick.