中文摘要：

本文设计了两种具有微结构纤芯的光子晶体光纤（PCFs）——矩形芯和椭圆芯PCFs,利用电磁场散射的多极理论研究了这两种光纤的基本特性.发现在光纤包层气孔不变的情况下,仅通过调节纤芯气孔的大小就可以灵活地调节光纤的双折射、色散和非线性特性.随着纤芯气孔半径r1的增大,两种纤芯结构的PCFs表现出如下特点：双折射度增大且最大双折射度对应的波长发生红移,零色散波长由一个增加到三个,短波段非线性系数增大而长波段非线性系数减小.r1=0.4μm的椭圆芯PCFs的三个零色散波长分别位于可见、近红外和中红外波段.在结构参数相似的情况下,椭圆芯PCFs比矩形芯PCFs更容易实现高双折射和高非线性.

英文摘要：

Photonic crystal fibers （ PCFs） with rectangle core and elliptical core have been designed. Their fundamental characteristics are studied by electromagnetic scattering theory of multipole method. It is found that the fiber birefringence,dispersion and nonlinear characteristics can be flexibly adjusted by changing the radius of the air holes in the core. The PCFs have the following characteristics：With the increase of radius r1 of air holes in the core,the birefringence increases and the wavelength corresponding to the maximum birefringence shifts towards the longer wavelength region,the number of zero-dispersion-wavelengths increases from one to three and nonlinear coefficient of the short-wave band decreases while it increases in the longer wavelength region. The three zero-dispersion-wavelengths of elliptical core PCFs with r1 = 0. 4 μm are located in visible,near-infrared and mid-infrared band,respectively. For similar structural parameters,elliptical core PCFs can achieve high birefringence and high nonlinearity more readily than rectangular core PCFs.