摘要

Quadratic parametric processes in a one-dimensional nonlinear structure were investigated by using a nonlinear transfer matrix and iterative algorithm. Our method can provide an accurate description in the regime of pump depletion. Detailed analysis shows iteration is important for achieving a precise result. In order to simplify the complex iterative derivation, we develop a simplified model for quasi-phase-matched (QPM) second harmonic generation. We extend the simplification strategy to treat other quadratic nonlinear interactions in a QPM structure. The validity of simplification is demonstrated by numerically comparing conversion efficiencies. Our method provides a simple and efficient way to investigate second-order parametric processes in QPM structures.