设计了基于正四边形晶格空气孔排列的光子晶体光纤,并在此基础上,通过在纤芯附近引入不同的微结构空气孔,运用全矢量有限元差分法,对不同微结构的光子晶体光纤的模式有效折射率、限制损耗、模场有效面积、非线性系数、波导色散系数等特性参数进行了仿真与分析。结果表明:引入不同的微结构,可以减小有效模场面积和增大非线性系数;引入正四边形微结构空气孔时,其限制损耗整体变化幅度较小;引入正八边形微结构空气孔时,其对应的波导色散系数在中波段变化比较平坦,且在波长为1 550 nm处波导色散系数接近于零;引入正十二边形微结构空气孔时,其波导色散系数均为负值且变化幅度不大,可以应用于光纤的色散补偿。根据对引入不同微结构的光子晶体光纤的特性研究,为进一步研究光子晶体光纤提供一定的参考。

In this paper,we introduce different microstructure air holes near the core based on the photonic crystal fiber arrayed with regular quadrilateral lattice air holes.The full vector finite element method for the different microstructure photonic crystal fiber is used to simulate and analyze the mode effective refractive index,limiting loss,effective area of mode field,nonlinear coefficient,waveguide dispersion and so on.The results show that the variation of the limiting loss is small when the positive quadrilateral micro-structure air hole is introduced.The introduction of microstructures allows smaller effective mode field areas and increased nonlinearity.When the octagonal microstructure air hole is introduced,the corresponding waveguide dispersion coefficient is relatively flat in the middle band,and the waveguide dispersion coefficient is close to zero at the wavelength of 1 550 nm.When the positive biaxial microstructural air holes are introduced,the total dispersion coefficients are negative and the variation range is not large,which can be applied to the dispersion compensation of the fiber.According to the research characteristics of the different microstructural photonic crystal fiber,we provide a reference value for the further study of designing the photonic crystal fiber.