中文摘要：

本文研究了纤芯结构对空芯光子晶体光纤光子带隙和传输损耗的影响，得到了适合光纤制备工艺的纤芯结构．首先利用平面波展开法计算了一定占空比三角形结构的空芯光子晶体光纤的带隙结构，给出了在传输波长λ=1．55μm时光纤的结构参数值，并模拟了纤芯直径对带隙位置和大小的影响，得出纤芯直径的取值范围，通过分析泄露损耗特性得出纤芯壁厚的取值．然后根据分析结果设计出了光纤端面图，运用全矢量有限元法模拟出在不同纤芯直径的情况下的模场分布，通过对比分析得出光纤的最佳纤芯半径R为1．6以-1．75A．研究结果表明，选择合适的纤芯结构既能满足空芯光子晶体光纤的光子带隙和损耗特征，又可以适当降低光纤制备工艺的难度．

英文摘要：

In this paper, the influences of fiber core structure on photonic band gap and transmission loss for hollow-core photonic crystal fiber are investigated, and the proper fiber core structure of fiber preparation technology is obtained. First, the band gap structure of triangular lattice of hollow core photonic crystal fiber with a fixed duty ratio is calculated by using plane wave expansion method. When the transmission wavelength λ=1.55μm, the structural parameters of the optical fiber are figured out. The value range of the core diameter is given by simulating the influences of core diameter on the band gap location and size, and the value of core wall thickness is obtained through analyzing the leak loss characteristics. Then the fiber end view drawing is designed according to the analytical results. The mode field distributions are simulated by the full-vectorial finite element method under different core diameters. Through the contrast analysis the best fiber core radius with R = 1.6 A--1.75 A is obtained. The results indicate that choosing appropriate core structure not only can meet the photonic band gap and loss characteristics of hollow-core photonic crystal fiber, but also can properly reduce the difficulty in the preparation technology of fiber.