ITMO University, St. Petersburg 197101, Russia.
Nonlinear Physics Center, Australian National University, Canberra Australian Capital Territory 2601, Australia.
Phys Rev Lett. 2018 Oct 19;121(16):163901. doi: 10.1103/PhysRevLett.121.163901.
Topological photonics has emerged recently as a smart approach for realizing robust optical circuitry, and the study of nonlinear effects is expected to open the door for tunability of photonic topological states. Here we realize experimentally nonlinearity-induced spectral tuning of electromagnetic topological edge states in arrays of coupled nonlinear resonators in the pump-probe regime. When nonlinearity is weak, we observe that the frequencies of the resonators exhibit spectral shifts concentrated mainly at the edge mode and affecting only weakly the bulk modes. For a strong pumping, we describe several scenarios of the transformation of the edge states and their hybridization with bulk modes, and also predict a parametrically driven transition from topological stationary to unstable dynamic regimes.
拓扑光子学最近作为一种实现稳健光学电路的智能方法而出现，对非线性效应的研究有望为光子拓扑态的可调谐性开辟道路。在这里，我们在泵浦探测实验中实现了耦合非线性谐振器阵列中电磁拓扑边缘态的非线性诱导光谱调谐。在非线性较弱的情况下，我们观察到谐振器的频率表现出主要集中在边缘模式且仅弱影响体模的光谱位移。对于强泵浦，我们描述了边缘态的几种转换情况及其与体模的杂化，还预测了从拓扑稳定到不稳定动力学的参数驱动跃迁。
