采用有限差分方法计算出Ge20Sb15Se65脊形波导的有效模式折射率,系统地分析了1550nm光通信波长上的波导准TM基模的群速度色散特性与波导关键结构参数之间的关系。大量模拟结果表明:较大的材料色散可以通过设计亚微米波导结构得到降低。在脊宽和脊高分别控制在500～900nm和400～1000nm范围内的情况下,通过增大波导的刻蚀深度能获得零色散甚至反常色散。另外,波导脊高变化比脊宽变化对色散的影响更大。研究结果为应用于非线性全光器件的硫系光波导提供了尺寸设计和色散管理的依据,对用于全光信号处理的硫系玻璃光波导器件的设计具有一定的参考价值。 The effective mode refractive index of the Ge20Sb15Se65 ridge waveguide was calculated by the finite difference method. The relationship between the group velocity dispersion of waveguide quasi TM base modes and the key structural parameters of the waveguide was systematically analyzed. A large number of simulation results show that larger material dispersion can be reduced by designing a sub-micron waveguide structure. When ridge width and ridge height are controlled in the range of 500 ~ 900nm and 400 ~ 1000nm respectively, zero-dispersion and even anomalous dispersion can be obtained by increasing the etching depth of waveguide. In addition, the variation of waveguide ridge height has more influence on the dispersion than the change of ridge width. The results provide the basis for dimension design and dispersion management for sulfur-based optical waveguides used in nonlinear all-optical devices, and have certain reference value for the design of sulfur-based glass optical waveguide devices for all-optical signal processing.