中文摘要：

通过在纤芯引入非均匀分布的高折射率介质柱，获得了大模场面积、平顶型模场分布的新型微结构光纤．运用数值仿真，分析了光纤在不同的结构参数下的模场面积、基模模场分布等特性．研究结果表明：通过合理设计光纤的包层和纤芯参数，可以实现有效的平顶模场分布．在工作波长为1064nm时，平项光纤的基模模场面积可以达到1655μm2．

英文摘要：

A novel microstructured-core optical fiber with large mode area and flat-topped mode field distribution is proposed. The core of the fiber is composed of high refractive index dielectric cylinders with a non-uniform distribution. Numerical simulation on the mode area, mode field distribution of the fundamental mode and other aspects of the fiber indicates that the fiber can effectively obtain fiat-topped mode field distribution by tuning the parameters of the cladding and the core of the fiber. In addition, the fiat-topped fiber has a large mode area of 1655 um2 at the operating wavelength of 1064 nm.