利用多极法结合耦合模理论对一种基于结构性改变的光子晶体光纤光栅进行了研究，建立了其结构模型，理论分析了此种成栅工艺原理。计算了七层三角形对称排布空气孔包层有效折射率随波长变化情况，比较了不同光子晶体光纤结构成栅效果的差异。研究结果表明，光子晶体光纤包层中空气孔周期性塌缩可以形成光栅，空气孔排布层数、空气孔占空比、空气孔塌缩层数和塌缩程度等参数对光子晶体光纤光栅的传输特性有重要影响，得出了谐振波长和谐振带宽与上述参数之间的变化关系，并给出这种变化关系的解释。

A kind of photonic crystal fiber grating based on structural change was studied by using the multipole method and the coupled mode theory, the structure model was built, and the principle was analyzed. The effective refractive indexes of the cladding with seven rings of the hexagonal symmetry air-holes varying with the wavelength were computed. Moreover, the performance differences of the gratings fabricated by the different photonic crystal fibers were compared. It was shown that the periodic air-holes shrinkage could form grating, and the number of rings of the air-holes in the cladding, the duty ratio of the air-holes, the number of rings of the air-holes shrinkage and the extent of the air-holes shrinkage had the important impact on the transmission characteristics of the photonic crystal fiber grating. Furthermore, the functional relationships that the resonance wavelength and bandwidth varied with these parameters were obtained and the rational explanations were given.