Effect of Surface Nonlinearity Distribution on Second Harmonic Generation under Tightly Focused Beams

Abstract

A thorough integral formulation describing the second harmonic generation under tightly focused linearly and radially polarized beams for an arbitrary distribution of the nonlinear susceptibility over the surface of isotropic media was presented. We numerically simulated effects caused by the straight edge of the nonlinear region. In particular, we demonstrated that the second harmonic radiation in the normal direction, which is forbidden in common cases of highly symmetrical nonlinear surfaces, is allowed in the presence of the edge. This is provided by χ(2)xzx-component of the second-order susceptibility.