三层外空气孔对光子晶体光纤非线性和色散的影响

Influence of the Outer Air-holes beyond the Third Ring on the Nonlinearity and Dispersion of Photonic Crystal Fibers

在以1550nm为中心的宽带波长范围内设计了一种宽带低非线性色散补偿光子晶体光纤,采用矢量光束传输法数值模拟了包层中空气孔层数、空气孔直径和空气孔节距对于其色散和非线性特性的影响。计算结果表明,内六层空气孔对于其色散与非线性特性有较强影响。通过优化调节第四到六层空气孔的直径和空气孔节距,设计了在以1550nm为中心的100nm带宽波长范围内对相当于自身长度190倍的普通单模传输光纤进行色散补偿的光子晶体光纤(色散补偿偏移率保持在0.5%以内),在此宽带波长范围内保持非线性系数低于3W-1?km-1。

A photonic crystal fiber for broadband dispersion-compensating with low nonlinearity in a wide wavelength range centered at 1 550 nm is designed,and the effects of the number of air-hole rings,the air-hole diameter and the lattice pitch on both dispersive and nonlinear properties are numerically described by using the vectorial beam propagation method.The results indicate that the inner six air-hole rings have stronger impact on the dispersive and the nonlinear properties.By optimizing and adjusting the diameters of the inner 4th to 6th air-holes and the lattice pitch,the proposed photonic crystal fiber can compensate（to within 0.5%） the dispersion of 190 times of its length of standard single mode transmission fiber over the entire 100nm band centered at 1 550 nm,while also can remain the nonlinear coefficient lower than 3 W-1？km-1 over the wide wavelength range.