Feng Yadian, Zhang Zhanyuan, Qin Feifei, Lan Zhihao, Sha Wei E I, Xu Yi
Opt Lett. 2022 Jun 15;47(12):3107-3110. doi: 10.1364/OL.463458.
Topological valley photonics provides a unique way to manipulate the flow of light. In general, valley edge states that exhibit unidirectional propagation and are immune to defects and disorders could be realized at the interface between two valley photonic crystals with opposite valley Chern numbers. Herein, by merging the physics of valley edge states and bound states in the continuum, we propose and numerically demonstrate a novel, to the best of our knowledge, concept of edge states termed bound valley edge states in the continuum, which enjoys the topological features of valley edge states, such as, unidirectional propagation and immunity to disorders, but are formed at the interface between air and a single valley photonic crystal. Our results not only provide an effective way to reduce the size of valley photonic structures but also facilitate new applications where the proposed concept of bound valley edge states in the continuum could be exploited for optical sensing and unidirectional waveguiding.
拓扑谷光子学提供了一种独特的方式来操纵光流。一般来说，在具有相反谷陈数的两个谷光子晶体之间的界面处，可以实现表现出单向传播且不受缺陷和无序影响的谷边缘态。在此，通过融合谷边缘态和连续统中的束缚态的物理原理，我们提出并通过数值证明了一种据我们所知新颖的边缘态概念，即在连续统中的束缚谷边缘态，它具有谷边缘态的拓扑特征，如单向传播和对无序的免疫性，但形成于空气与单个谷光子晶体之间的界面处。我们的结果不仅提供了一种有效减小谷光子结构尺寸的方法，还促进了新的应用，在这些应用中，所提出的连续统中的束缚谷边缘态概念可用于光学传感和单向波导。
