针对交叉多模光波导结构，基于光束传输法（Beam Propagation Method, BPM）对其传输特性进行了分析，通过对方形多模光波导模式Exp,q的分析发现，对于相同的模式序数p，随着传输模式阶数q的增加，交叉光波导的传输特性基本保持不变；随着模式序数p的增加，小的交叉角度更易引起交叉光波导的相互干扰。

For multimode optical waveguides, the mode transmission becomes especially complex. In this work, the crossing structure consisting of two multimode waveguides was analyzed by using beam propagation method (BPM). From the analysis of the modes of Exp,q, it was found that the transmission modes were almost same for the same subindex p with the increasing subindex q. And the optical power crosstalk becomes strong between the two crossing waveguides for smaller crossing angles.