设计了一种基于四孔单元的光子晶体光纤,它可以满足光通信系统中高双折射率、负色散和低限制损耗的要求,比起通常的三角结构光纤有着更高的双折射率,并且结构制作也较简单。采用全矢量有限元法和各项异性完美匹配层法对所设计的光纤进行了仿真研究。仿真结果表明:该光纤在1.55μm波长处可获得10~(-2)数量级的双折射率,在较宽广的波段范围具有大的负色散,限制损耗低于10~(-9)dB/m;该光纤在保偏光纤、单极化单模光纤、色散补偿光纤等方面具有重要的应用。 A four-hole unit-based photonic crystal fiber is designed to meet the requirements of high birefringence, negative dispersion and low limit loss in optical communication systems, and has a higher birefringence than the conventional triangular structure fiber. The structure Production is also relatively simple. The full-fiber finite element method and perfect heterosexual matching layer method were used to simulate the designed optical fiber. The simulation results show that the fiber has a birefringence of 10 ~ (-2) at the wavelength of 1.55μm, a large negative dispersion in a wide band and a limit loss of less than 10 -9 dB / m The fiber has important applications in polarization-maintaining fiber, single-polarization single-mode fiber, dispersion compensation fiber and the like.