Dynamics of parametric holographic-type scattering of light

A study was made of the dynamics of degenerate parametric scattering of light in photorefractive LiNbO₃ crystals. A numerical solution was obtained of a system of reduced equations for the amplitudes of the interacting waves, which described well the experimental results. Three characteristic stages of the development of the scattering were identified: spontaneous, stimulated, and saturation. The experimentally determined spectral–angular brightness of the noise seed radiation, which induced scattering in the spontaneous regime, was considerably higher than the calculated brightness resulting from the Rayleigh scattering of pump radiation by optical inhomogeneities of the investigated crystal.