Topological photonics provides a novel route for designing and realizing optical devices with unprecedented functionalities. Topological edge states, which are supported at the boundary of two photonic systems with different band topologies, enable robust light transport immune to structural imperfections and/or sharp bends in waveguides. Furthermore, the topological edge states are expected to revolutionize cavity-based optical devices such as lasers. Optical devices with built-in topological protection with a small footprint are fascinating as on-chip optical devices for low-loss and functional photonic integrated circuits. Semiconductor photonic crystals are promising platforms enabling the miniaturization of topological optical devices. Herein, we review the recent realizations of semiconductor topological photonic crystals. In particular, we discuss topological waveguides in valley photonic crystals, which have received increasing attention because of their simple realization. In addition, we provide recent demonstrations of topological nanocavities, which are another key component of topological nanophotonics. Progress in semiconductor topological photonic crystals will propel the use of topological photonic devices in various applications as well as deepen the understanding of topological photonic phenomena at the wavelength scale.

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半导体光子晶体平台中拓扑波导和纳米腔的最新进展[已邀请]

拓扑光子学为设计和实现具有空前功能的光学设备提供了一条新颖的途径。拓扑边缘状态在两个具有不同带形拓扑的光子系统的边界处得到支持，从而使鲁棒的光传输不受结构缺陷和/或波导中的急剧弯曲的影响。此外，预期拓扑边缘状态将彻底改变基于腔的光学设备（例如激光器）。具有内置拓扑保护，占用空间小的光学设备非常引人注目，它们是用于低损耗和功能性光子集成电路的片上光学设备。半导体光子晶体是使拓扑光学设备小型化的有前途的平台。本文中，我们回顾了半导体拓扑光子晶体的最新实现。特别是，我们讨论了山谷光子晶体中的拓扑波导，由于它们的简单实现，它们受到了越来越多的关注。此外，我们提供了拓扑纳米腔的最新演示，这是拓扑纳米光子学的另一个关键组成部分。半导体拓扑光子晶体的进步将推动拓扑光子器件在各种应用中的使用，并加深对波长范围的拓扑光子现象的理解。