七芯及十九芯大模场少模光纤的特性研究和比对分析

摘要

提出了一种新型的多芯大模场少模光纤.包含缺失空气孔的特殊结构使其具有独特的少模特性，仅传输HE11模和HE21模.分析表明七芯大模场少模光纤能维持稳定的双模式运转，且基模有效面积可达866.54µm2.系统研究了光纤结构参数影响模式特性和基模有效面积的规律，并分析了纤芯数目增加带来的性能相似性和差异性—–进阶的十九芯大模场少模光纤在继承少模特性的同时，模场面积大大增加，其基模有效面积可高达3617.55µm2.对比已报道的少模光纤，多芯大模场少模光纤获得了更大的有效面积，并具有良好的弯曲特性，有望被用于更高功率的光纤放大器、光纤激光器以及高速大容量光纤传输系统中.%A novel multi-core large-mode-area few-mode fiber (MC-LMA-FMF) is proposed in this paper. The special structure of air holes makes it operate in few modes (HE11 and HE21 mode only). Numerical analysis shows that the 7-core-LMA-FMF can maintain a stable dual-mode operation and the effective area of the fundamental mode can reach 866.54 µm2. The regular pattern that fiber structure parameters affect mode characteristics and the effective area is investigated, and the similarities and differences brought in by increasing the number of cores is also analyzed. The advanced 19-core-LMA-FMF inherits the few-mode characteristic, meanwhile, the effective area of the fundamental mode can be as high as 3617.55 µm2. Compared with the reported few-mode fibers, MC-LMA-FMF obtains a large effective area and good bending characteristics. These advantages enable this new type of fiber to be a potential candidate for high-speed large-capacity optical fiber transmission systems or high power fiber amplifiers and lasers.