MMI器件模式传输分析法与精确模式分析法比较

本文对广泛使用的多模干涉（MMI）器件近似分析方法－－MPA法与精确模式分析方法－－EMA法在基本原理和具体应用上进行了详细的比较和分析。结果表明：计算量少、方便简单的MPA在高次模的传播常数和场分布两个方面都存在较大误差。这两个因素使用MPA仅在分析各端口都有较大输出的MMI器件时误差较小；而对某端口的输出有尽量小的要求的器件进行分析时，会得出过于乐观的结果，此时应采用精确但较繁琐的EMA分析。

Compare of Two Numerical Methods for MMI Devices

Modal propagation analysis (MPA) and exact mode analysis (EMA) are compared in this paper.Analysis on basic principles and applications of these two methods are performed.As an appoximate method,MPA is convenient and simple,however,it has more errors on propagation constants and field distributions of high order modes.Thus it is not accurate enough when used on devices which acquire low output at one or more output ports.And EMA,which is an accurate method despite of its complicated process,should be used at this time.