An effective susceptibility model for exact solution of second harmonic generation in general quasi-phase-matched structures

We present a universal effective nonlinear susceptibility model to analyze second harmonic generation (SHG) in general quasi-phase-matched (QPM) structures. The model derives directly from nonlinear coupled wave equations and agrees excellently with rigorous numerical calculations. It has allowed us to handle successfully general situations of low and high nonlinear conversion efficiency for arbitrary orders of forward and backward processes in periodic and quasi-periodic QPM structures. By means of the analytical model, one can evaluate practical samples conveniently and accurately and design optimum QPM structures for various applications. Copyright (C) EPLA, 2011