用有效折射率方法对SOI(绝缘体上硅 )及GeSi Si脊形光波导的单模条件进行了模拟 ,与Soref的单模条件进行了比较 ,将两者与实验结果进行了比较 ,得到了与实验结果符合得非常好的单模条件。同时对多模波导进行了模拟 ,得到了波导承载一阶和二阶模的条件 The single mode conditions of SOI (silicon on insulator) and GeSi Si ridge optical waveguides are modeled by the effective refractive index method, and compared with the Soref single mode condition, the two are compared with the experimental results, The experimental results are in good agreement with the single-mode conditions. At the same time, the multimode waveguide was simulated and the condition of waveguide carrying first and second order modes was obtained