提出了一种易研制的高双折射双零色散波长新型光子晶体光纤。其包层由采用2种不同尺寸的圆形空气孔按照类矩形和三角形晶格排列而成。运用全矢量有限元法对其光学特性进行理论模拟分析, 结果表明, 当d1=0.80 μm, d2=1.10 μm, Λ=1.00 μm时, 在1.55 μm波长处获得2.59×10-2的双折射, 且在X、Y偏振方向的非线性系数分别为46 km-1·W-1和36 km-1·W-1。同时, 该光纤在可见光和近红外波段具有2个零色散点, 色散点间距为0.68 μm。通过设置合理的参数, 双零色散点位置、色散点间距以及色散曲线的平坦性可调。采用现有拉制工艺, 该结构的光纤易于研制, 有利于该光纤在超连续谱产生、偏振系统控制、光纤传感等领域的大规模应用。

A kind of novel photonic crystal fiber with easy fabrication, high birefringence and double zero-dispersion is proposed. The cladding is made of two circular air holes of different sizes in the form of quasi-rectangular and triangular lattices. The optical characteristics are analyzed by the full vector finite element method. The results show that birefringence of 2.59×10-2 is obtained at wavelength of 1.55 μm when d1 =0.80 μm, d2=1.10 μm, Λ=1.00 μm, and nonlinear coefficients in X and Y polarization directions are 46 km-1·W-1 and 36 km-1·W-1, respectively. In addition, two zero-dispersion points are located in the visible and near-infrared bands and distance between two dispersion points is 0.68 μm. Through reasonable parameter setting, positions of double zero-dispersion points, dispersion points spacing and flatness of dispersion curve are adjustable. The optical fiber with the structure is easy to fabricate in existing drawing process, which will be conducive to large-scale applications of the fiber in the supercontinuum generation, polarization system control and optical fiber sensing.