论文标题
Su-Schrieffer-Heeger光子晶格中的弱非线性拓扑间隙孤子
Weakly nonlinear topological gap solitons in Su-Schrieffer-Heeger photonic lattices
论文作者
论文摘要
我们从理论和实验上研究非线性对光子Su-Schrieffer-Heeger（SSH）晶格中拓扑保护的线性界面模式的影响。结果表明，在焦点或散落非线性下，这种SSH晶格的线性拓扑模式变成了拓扑间隙孤子的家族。这些孤子是稳定的。但是，它们仅表现出低振幅和功率，因此即使SSH晶格的带隙宽，也是弱的非线性。结果，如果初始光束具有适度或高功率，则它将脱位或演变成不属于拓扑间隙孤子家族的孤子。这些理论预测在我们的实验中使用光学诱导的SSH型光致热晶格观察到。
We study both theoretically and experimentally the effect of nonlinearity on topologically protected linear interface modes in a photonic Su-Schrieffer-Heeger (SSH) lattice. It is shown that under either focusing or defocusing nonlinearity, this linear topological mode of the SSH lattice turns into a family of topological gap solitons. These solitons are stable. However, they exhibit only a low amplitude and power and are thus weakly nonlinear, even when the bandgap of the SSH lattice is wide. As a consequence, if the initial beam has modest or high power, it will either delocalize, or evolve into a soliton not belonging to the family of topological gap solitons. These theoretical predictions are observed in our experiments with optically induced SSH-type photorefractive lattices.
