中文摘要：

设计了一种新型的光子晶体光纤（PCF）合束器，利用光子晶体光纤的后处理技术塌缩纤芯周围的三圈空气孔使纤芯直径增大，再对PCF合束器进行熔融拉锥，将多路熔融拉锥后的光子晶体光纤熔接到一路多模光纤作为输出端。通过数值模拟计算得到：扩芯-拉锥PCF合束器在入射不同波长时的轴向损耗远小于直接拉锥PCF合束器。

英文摘要：

A novel design of photonic crystal fiber （PCF） combiners is demonstrated. First, collapse three rings of air holes near to the fiber core using the post-processing techniques of PCFs, to enlarge the core. Then, taper it. Finally, splice the tapered multi-photonic crystal fibers into a multimode fiber for output. The axial losses of the directly tapered combiners and the expanded core-tapered combiners at different incident wavelengths are simulated and compared. The results show that the transmission losses of the expanded core-tapered combiners are far below those of the combiners without using the technology.