运用光束传播法和有效折射率法分析了大截面单模半导体脊形交叉波导结构的传输特性，对Ｙ形，Ｘ形和加宽Ｘ形结构进行了比较.结果表明，在小交叉角时，三种结构具有相似的传输特性；在大交叉角时，它们表现出较大的差异.而在Ｙ型结构中，不存在模式干涉.

This paper presents a general theoretical investigation of the crossing waveguidestructures constructed by large-size single-mode rib semiconductor waveguides. The theoretical model is based on beam propagation method and effective index method. Three kinds of structure are analysed and compared. The numerical results show that these structures exhibit similar characteristics at large crossing angles but divergences exist at small crossing angles. It is found that mode-interference dose not exist in y-junction.