Recently, topologically engineered photonic structures have garnered significant attention, as their eigenstates may offer a new insight on photon manipulation and an unconventional route for nanophotonic devices with unprecedented functionalities and robustness. Herein, we present lasing actions at all hierarchical eigenstates that can exist in a topologically designed single two-dimensional (2D) photonic crystal (PhC) platform: 2D bulk, one-dimensional edge, and zero-dimensional corner states. In particular, multiple topological eigenstates are generated in a hierarchical manner with no bulk multipole moment. The unit cell of the topological PhC structure is a tetramer composed of four identical air holes perforated into an InGaAsP multiple-quantum-well epilayer slab. A square area of a topologically nontrivial PhC structure is surrounded by a topologically trivial counterpart, resulting in multidimensional eigenstates of one bulk, four side edges, and four corners within and at the boundaries. Spatially resolved optical excitation spontaneously results in lasing actions at all nine hierarchical topological states. Our experimental findings may provide insight into the development of sophisticated next-generation nanophotonic devices and robust integration platforms.

中文翻译：

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二维光子晶体结构中处于多维拓扑状态的激光

最近，拓扑工程光子结构受到了广泛的关注，因为它们的本征态可能为光子操纵提供新的见解，并为具有前所未有的功能和鲁棒性的纳米光子器件提供了一条非常规的途径。在本文中，我们介绍了在拓扑设计的单个二维（2D）光子晶体（PhC）平台中可能存在的所有分层本征态的激射作用：2D体，一维边缘和零维角状态。特别地，以分层的方式产生多个拓扑本征态，而没有本体多极矩。拓扑PhC结构的晶胞是一个四聚体，由四个相同的气孔组成，这些气孔打入InGaAsP多量子阱外延层平板中。拓扑无关紧要的PhC结构的正方形区域被拓扑无关紧要的对等物包围，从而在边界内和边界处产生一个整体，四个侧边和四个角的多维本征态。空间分辨的光激发自发地导致在所有九个分层拓扑状态下的激射作用。我们的实验结果可能会提供对复杂的下一代纳米光子器件和强大的集成平台开发的见识。