金属包层渐变折射率平板介质波导导模的二阶微扰分析

本文由微扰理论和多层分析法得到了金属包层波变折射率介质波导导模的传播常数的一级和二级近似结果，同时直接求得了复本征方程的解，将两者进行分析比较，结果表明微扰法是相当好的近似方法，它们给出了与精确值符合相当好的数值结果。分析结果还表明微扰法的二级近似结果对一级近似结果的修正很小，一级近似已可以给出足够精确的结果。

Second Order Perturbation Analysis of Guided Modes in Metal-Clad Grade Index Planar Wave-Guide

The complex eigenvalue equation of a metal\|clad grade index planar wave\|guide is solved exactly.The results of the first and the second order approximation obtained by using the perturbation theory and multi\|layer approximation method are compared with exact results.It is demonstrated that the perturbation and multi\|layer approximation method gives results in good agreement with those obtained by exact solution of complex eigenvalue equation.It is also demonstrated that the difference between results of the first and the second order approximation is quite small and usually the first order approximation gives sufficiently accurate results.