复合六边形空气孔格点光子晶体光纤的色散特性分析

Dispersion Properties of Photonic Crystal Fiber with Composite Hexagonal Air Hole Lattice

提出了一种复合六边形空气孔格点光子晶体光纤，其包层是由两种不同大小的空气孔组合而构成的。利用带有良匹配层（APML）吸收边界的全矢量频域有限差分法（FDFD）对其色散特性进行了数值分析。结果表明，通过调节包层中两种不同尺寸的空气孔的大小以及孔间距这三个参量，可以得到不同水平的平坦色散曲线，甚至超低超平坦的色散曲线。在孔间距A取2．1μm，小尺寸空气孔直径取0．5μm，大尺寸空气孔直径取0．8μm的条件下，在1．48～1．78μm的波长范围内得到了0±0．545ps／（km·nm）的色散。

A new photonic crystal fiber （PCF） with composite hexagonal air hole lattice is proposed and analyzed using the full-vector finite difference frequency domain （FDFD） method with anisotropic perfect match layer （APML） absorbing boundaries. We numerically demonstrate that the flattened dispersion of different levels, even the nearly zero ultra-flattened dispersion characteristics can be achieved through optimizing three geometrical parameters, two for air-hole diameters and one for hole pitch. As an example, the dispersion is 0±0. 545 ps/（km · nm） from 1.48μm to 1.78μm wavelength when A, d1 and d2 are 2.1 μm, 0.5 μm, 0.8 μm respectively. The flattened dispersion feature makes it suitable for the wavelength-division multiplexing communication systems and nonlinear optics.