设计了一种具有高对称性模场分布的高双折射光子晶体光纤(PCF)结构,由尺寸相同的椭圆空气孔菱形排列组成。利用全矢量有限元法对该种结构光子晶体光纤的基模场分布、有效模场面积、双折射和色散进行数值分析,所得结果与相同结构参数的圆形空气孔光子晶体光纤进行比较。这两种光纤的模场均具有高对称性,近似圆形,并且易于与光器件中其他光纤耦合。椭圆空气孔光子晶体光纤的双折射可达10-3。
A high symmetry of the mode field distribution and high birefringent photonic crystal fiber(PCF) is presented,with uniform size of ellipse air holes arranging like diamond.A full-vector finite element method is used to simulate the fundamental mode field distribution,effective mode area,birefringence and dispersion.Circle air-holes PCF with the same parameters are also computed to compare with it.Both of the fibers have high symmetry mode field and nearly circular,which makes it couple with other fibers in optical devices easily.It achieves high birefringence of elliptical air-holes PCF up to 10-3.