Parametric Intermode Scattering in LiNbO3 Planar Waveguides

Practically all nonlinear frequency degenerate four wave mixing processes reported previously for the bulk photorefractive materials have been observed also in the planar photorefractive waveguides: interaction of two beams with the same (or with the different) mode indices resulting in the developement of the dynamic grating, phase conjugation due to the backward wave mixing, polarization conversion, etc.[1]. Specific properties of the waveguides, as, e.g., the existance of several propagation modes with the same frequency but different propagation velocities, make possible same additional nonlinear wave mixing effects which do not occure in bulk samples. We report the first to our knowlage observation of such effect-the nonlinear parametric mixing of different waveguide mode and parametric intermode scatering.