Mode Analysis of Photonic Crystal Fiber in Finite Element Method with 2nd-order Transparent Boundary Conditions

摘要

The finite element method with 2nd -order transparent boundary conditions is proposed to analysis the modes of photonic crystal fibers. These boundary conditions preserve the sparse matrix and offering accuracy of O(r~(-9/2)), here r denoting the position of the computational boundary with respect to a chosen origin of the structure. The effective mode-index, the mode distribution, the confinement loss and the dispersion properties of the total internal reflection photonic crystal fibers (TIR-PCF) with triangle lattices and rectangle lattices are calculated in this method respectively. The results agree with the published results. At the same time the finite element method in the paper lessens the computation domain remarkably. It offers an easy and credibility approach in the study on the PCF and other fibers with irregular cross-section index distribution, even fibers with anisotropy materials.