针对一种圆形晶格微结构光纤,采用有限差分波束传播法对多孔光纤的模式双折射特性进行数值模拟。通过分析横截面结构参数的变化对模式双折射的影响,得到了合适的光纤结构参数,其偏振拍长可以在1310nm附近较宽的波长范围内基本保持稳定,工作带宽可达200nm,具有较好的消色差特性。这种结构的光纤适合制作宽带稳定的消色差波片。 Aiming at a circular lattice microstructure fiber, the mode birefringence of porous optical fiber is numerically simulated by finite difference beam propagation method. By analyzing the influence of the change of cross-section structure parameters on the mode birefringence, suitable optical fiber structure parameters are obtained, and the polarization beat length of the fiber can be basically stabilized within a wide wavelength range around 1310 nm with a working bandwidth of up to 200 nm, which is better Achromatic characteristics. This structure of fiber suitable for the production of broadband stable achromatic wave plate.