设计了一种新型高负色散光子晶体光纤,其纤芯由三根空气柱形成,三种 孔径大小不同的空气柱以六角点阵方式排列。基于全矢量有限元法,结合各向异 性完美匹配层边值条件对光子晶体光纤的色散、模场、非线性、约束损耗和双折射 等特性进行了数值计算。结果表明光纤结构参数Λ、d、d1、d2分别为1.15、0.88、0.83、1.14μm时, 该光纤在低损耗通信窗口C波段呈现高负色散,在波长1.55μm处负色散值、双折射、约束损耗、 非线性系数分别为-11660 ps·km-1·nm-1、2.03×10-3、10-3 dB·km-1、 7.33 km-1·W-1。可见该光纤在低损耗通信窗口C波段呈现高负色散、低损耗、高双折射、低非线性, 具有很好的色散补偿能力,有望在光通信系统中获得应用。

A novel photonic crystal fiber with high negative dispersion is proposed. The fiber core is formed by three air columns, and three air-holes with different diameters are arranged in hexagonal lattice cladding. The dispersion, mode field, nonlinearity, leakage loss and birefringence are numerically calculated based on full vector finite element method combining with anisotropic perfectly matched layers boundary condition. Results show that when the fiber structure parameters Λ,d,d1,d2 are 1.15, 0.88, 0.83, 1.14 μm, respectively, the fiber exhibits high negative dispersion in low-loss communication window C band. The negative dispersion, birefringence, leakage loss and nonlinear coefficient values are -11660 ps·km-1·nm-1,2.03×10-3,10-3 dB·km-1, 7.33 km-1·W-1 at 1.55 μm, respectively. It is shown that the optical fiber has high negative dispersion, low loss, high birefringence, low nonlinearity and good dispersion compensation ability in C band of low loss communication window, and it is expected to be used in optical communication system.