Formation of quasi-regular diffraction patterns in the nonlinear photorefractive Fabry-Perot interferometer

Formation of optical inhomogeneities under self-action of light fields in photorefractive Fabry-Perot interferometers has been experimentally investigated using the samples of Y — and Z-cut lithium niobate. For the interferometer with the Z-cut sample, it is demonstrated that spiral-shaped inhomogeneities and two-dimensional quasi-regular diffraction patterns are formed under the effect of the Gaussian beam about 1mm in diameter and the light field with a homogeneous intensity distribution.