切伦科夫型级联二阶非线性效应的解析优化

Analytical Optimization of Cherenkov Cascading Nonlinear Effects

在考虑传输损耗的基础上 ,用解析的方法详细分析和优化了平板波导中切伦科夫型级联二阶非线性效应引起的基波非线性相位移动和基波功率的变化 ,结果表明 ,基波非线性相位移动和基波功率变化对波导参数和光波波长有强烈的依赖关系。另外 ,即使不引入周期畴反转 ,只要对波导厚度和入射光波波长合理选择 ,就可以在基波功率消耗很小的情况下得到相当大的基波非线性相位移动 (>2π)。不引入畴反转可以避免制作高质量反转结构的技术困难 ,对该结构在全光开关器件中的实际应用有重要的价值。

The nonlinear phase shift and the changes of fundamental wave mmplitude caused by Cherenkov cascading second order nonlinearity have been analyzed and optimized, taking into account the propagation loss. According to author's calculation, the nonlinear phase shift and the change of fundamental power are strongly dependent on two parameters: the thickness of the waveguide and the fundamental light wavelength. The results show that a very large nonlinear phase shift (>2π) can be attained with a very small depletion of fundamental power even if the reversal period is not introduced into the waveguide by properly choosing the two parameters, which is very attractive to the realization of the all-optical switches. Many useful results are obtained which are important to the research and development of all-optical switches.