Effect of sample imperfections on far-field self-diffraction patterns of a Gaussian beam passing through Kerr media

摘要

Considering the nonlinear phase shift photoinduced by an imperfect Kerr medium, we investigate the far-field self-diffraction patterns of the Gaussian beam using the Huygens-Fresnel diffraction integral method. We analyze the distortion of self-diffraction patterns induced by the nonlinear samples with scratch, damaged spot, plano-convex lens effect, inhomogeneous thickness, wedged configuration, and gravitation-dependent molecular distribution. In principle, the far-field self-diffraction pattern could be illustrated with the known two-dimensional thickness of the nonlinear sample. Alternatively, the analysis of the self-diffraction pattern opens up a new avenue to evaluate the surface morphology of the nonlinear optical sample.