准相位匹配PPLN波导全光开关特性研究

Analysis of AO-dptical Switching in PPLN Waveguide with Phase-Mismatched Condition

本文利用一种具有半圆形极化畴结构的PPLN晶体,在慢变振幅近似条件下,基于二阶非线性效应并考虑到控制光和信号光简并二波耦合时周期性极化铌酸锂波导内的耦合模方程,用数值方法对小信号时相位失配情况下的全光开关特性进行了研究,分析了由于光栅周期、晶体温度和控制光波长变化引起的相位失配对输出的信号光功率的影响,并给出了输出信号光功率与控制光功率之间的关系曲线。发现在相位失配的情况下增大控制光的功率可以达到信号光的关断,具有较好的开关特性。

The characterization of all - optical switching is analyzed theoretically based on cascaded second - order nonlinear and degenerate two - wave mixing in the periodically poled LiNbO3 （PPLN） waveguide with homocentrically semicircle domain structure. The coupled equa- tions are given that describe the evolution of electric fields through lhe media derived from the slowly valying envelope approximation. Based on solving the couple mode equations numerically, the dependence of the signal power on the gate power is given under different phase mismatch conditions such as the grating period, the crystal temperature and the gate wavelength. The all-optical switching has better characteristic.