Light-induced symmetry breaking and related giant enhancement of nonlinear properties in CdZnTe:V crystals.

We report on enormous light-induced reversible strain effects in CdZnTe:V crystals, which lead to a remarkable enhancement of their nonlinear properties, such as electrostriction and electro-optic effects. Using both high resolution x-ray diffraction and optical interferometry we measure light-induced relative deformation of the initial crystalline lattice (changes in d-spacings) up to 0.15%. The experimental findings are attributed to light-induced breaking of the initial cubic crystalline symmetry. Our results point to a family of inorganic materials whose nonlinear properties can be remarkably enhanced by light, offering new possibilities for nonlinear frequency conversion, generation of Terahertz radiation, electro-optic modulation, and self-deflection of optical beams.