复折射率光纤传输特性的微扰分析

Perturbation Analysis for Optical Fibers with Complex Refractive-Index Profile

运用微扰分析方法计算复折射率光纤复传播常数 .光纤的复数模折射率N =N′ +iN″的实部N′由求解相应的实本征值方程得到 ,而虚部N″则由微扰计算得到 .对阶跃型圆光纤 ,导出了芯区或包层为复折射率时的损耗或增益的解析关系式 ,数值计算结果表明 ,本法与直接解复本征值方程得到的精确结果符合得很好 .

An accurate perturbation method for characteristic analysis of optical fibers with complex refractive index profile is presented. Analytic formulas are derived for the fundamental-mode of step-index circular fibers to calculate loss or gain of the fibers. Numerical results are good in agreement with those obtained by exact analysis.