Cascaded second order nonlinear processes for nonlinear optical applications

Abstract

A significant part of research on optical crystals is dedicated to nonlinear frequency newlineconversion for their several fields of applications. Among them, the second harmonic newlinegeneration is the most popular through nonlinear crystals, which are highly anisotropic newlineand non-centrosymmetric. However, anisotropic crystals having remarkable secondorder newlinenonlinear effects may develop large equivalent effective third-order nonlinearity newlinelarger than natural third-order nonlinearity developed by cascaded second-order newlinenonlinearities. The conversion efficiency of SHG is limited to the phase matching newlinebetween the fundamental and second harmonic waves, which several efficient nonlinear newlineinteraction techniques with certain limitations can improve. newline