Coupling of orthogonally polarized eigenwaves in BaTiO3 by light-induced parametric scattering

Efficient indirect recording of space-charge gratings by two orthogonally polarized light waves is shown to be possible in crystals with diffusion charge transport when pronounced light-induced scattering is involved. The recorded grating is pi/2 shifted with respect to the polarization fringes and therefore leads to a unidirectional intensity transfer between the pump waves; the direction of transfer depends on the sign of photoexcited carriers. The relatively strong coupling effects between ordinary and extraordinary waves, detected experimentally in BaTiO3, are reasonably explained within the proposed model. (C) 1997 Optical Society of America.