Mutual transformation of the light waves by contra-directional mixing on reflection holographic grating in Bi-=SUB=-12-=/SUB=-SiO-=SUB=-20-=/SUB=- crystal of (001)-cut

Abstract

The features of energy exchange during the contra-directional mixing of two linearly polarized light waves in a cubic photorefractive Bi12SiO20 piezocrystal of (001)-cut are analyzed. The dependences of the relative intensity of the signal wave on the azimuth of its polarization at the entrance to the crystal during mixing with the reference wave polarized in the plane of incidence are theoretically studied for various crystal orientation angles. The dependence of the relative intensity of the signal wave on the azimuth of its polarization is experimentally studied for the cases when the vector amplitudes of light waves propagating in the crystal are parallel and perpendicular to each other. The calculation is based on the numerical solution of the coupled waves equations with and without taking into account the self-diffraction of the light waves by the reflection holographic grating recorded in the crystal. Based on a comparison of theoretical and experimental data, the influence of self-diffraction on the mutual transformation of light waves during their contra-directional mixing is analyzed. The limits of applicability of the static grating and the dynamic grating approximations for solution of the coupled waves equations are determined. Keywords: Photorefractive crystal, reflection holographic grating, coupled wave equations, self-diffraction.