Various topological laser concepts have recently enabled the demonstration of robust light-emitting devices that are immune to structural deformations and tolerant to fabrication imperfections. Current realizations of photonic cavities with topological boundaries are often limited by outcoupling issues or poor directionality and require complex design and fabrication that hinder operation at small wavelengths. Here we propose a topological cavity design based on interface states between two one-dimensional photonic crystals with distinct Zak phases. Using a few monolayers of solution-processed all-inorganic cesium lead halide perovskite quantum dots as the ultrathin gain medium, we demonstrate a lithography-free, vertical-emitting, low-threshold, and single-mode laser emitting in the green. We show that the topological laser, akin to vertical-cavity surface-emitting lasers (VCSELs), is robust against local perturbations of the multilayer structure. We argue that the design simplicity and reduction of the gain medium thickness enabled by the topological cavity make this architecture suitable for low-cost and efficient quantum dot vertical emitting lasers operating across the visible spectral region.

各种拓扑激光概念最近已经能够展示不受结构变形影响且容忍制造缺陷的坚固发光设备。目前对具有拓扑边界的光子腔的实现通常受到外耦合问题或方向性差的限制，并且需要复杂的设计和制造，这阻碍了在小波长下的操作。在这里，我们提出了一种基于具有不同 Zak 相的两个一维光子晶体之间的界面态的拓扑腔设计。使用一些单层溶液处理的全无机铯铅卤化物钙钛矿量子点作为超薄增益介质，我们展示了一种无光刻、垂直发射、低阈值和绿色单模激光发射。我们展示了拓扑激光器，类似于垂直腔表面发射激光器 (VCSEL)，对多层结构的局部扰动具有鲁棒性。我们认为，拓扑腔实现的设计简单性和增益介质厚度的减少使该架构适用于在可见光谱区域运行的低成本和高效的量子点垂直发射激光器。