Liang Li, Zhou Xiaoxi, Hu Jun-Hui, Wang Hai-Xiao, Jiang Jian-Hua, Hou Bo
Opt Lett. 2022 Mar 15;47(6):1454-1457. doi: 10.1364/OL.451770.
The recent advancements in higher-order topology have provided unprecedented opportunities in optical device designs and applications. Here, we propose a new, to the best of our knowledge, method to realize rainbow trapping based on higher-order topological corner modes (HOTCMs), which are constructed by two configurations of breathing kagome photonic crystals with distinct topological phases. Interestingly, the HOTCMs localized at corners with different geometric configurations are found to be frequency dispersive and thus initiate the possible application in realizing rainbow trapping. By designing a polygon structure containing several configurations of corners, we demonstrate that the HOTCMs can be excited with the frequency sequence locked to the corner order (clockwise/anticlockwise direction) in the polygon. The reported HOTCMs provide a new mechanism to realize multiple-frequency trapping, which may find potential applications in future integrated photonics.
高阶拓扑学的最新进展为光学器件设计与应用带来了前所未有的机遇。在此，据我们所知，我们提出了一种基于高阶拓扑角模式（HOTCMs）实现彩虹俘获的新方法，该模式由具有不同拓扑相的两种呼吸型 Kagome 光子晶体构型构建而成。有趣的是，发现位于具有不同几何构型角落处的 HOTCMs 具有频率色散特性，从而开启了在实现彩虹俘获方面的可能应用。通过设计一个包含多种角落构型的多边形结构，我们证明了 HOTCMs 能够以与多边形中角落顺序（顺时针/逆时针方向）锁定的频率序列被激发。所报道的 HOTCMs 提供了一种实现多频俘获的新机制，这可能在未来的集成光子学中找到潜在应用。
