Antikainen A, Agrawal G P
Opt Lett. 2019 Sep 1;44(17):4159-4162. doi: 10.1364/OL.44.004159.
Soliton propagation in seven-core fibers is studied numerically with the frequency dependence of linear coupling taken into account. It is shown that under certain conditions, solitons can undergo spontaneous supermode transitions upon abrupt red shift, analogous to the recently discovered phenomenon of soliton self-mode conversion in step-index multi-mode fibers. When the core separation is increased, the dynamics change drastically, leading to total suppression of soliton self-frequency shift and the emergence of spatially oscillating solitonic structures with resemblance to solitons in graded-index multi-mode fibers. The observed phenomena are general multi-core effects and not specific to seven-core fibers.
考虑到线性耦合的频率依赖性，对七芯光纤中的孤子传输进行了数值研究。结果表明，在一定条件下，孤子在突然红移时会发生自发的超模跃迁，类似于最近在阶跃折射率多模光纤中发现的孤子自模转换现象。当纤芯间距增加时，动力学发生剧烈变化，导致孤子自频移完全被抑制，并出现类似于渐变折射率多模光纤中孤子的空间振荡孤子结构。观察到的现象是一般的多芯效应，并非七芯光纤所特有。
