Topological lasers are of growing interest as a way to achieve disorder-robust single-mode lasing using arrays of coupled resonators. We study lasing in a two-dimensional coupled resonator lattice exhibiting transitions between trivial and topological phases, which allows us to systematically characterize the lasing modes throughout a topological phase. We show that, unlike conventional topological robustness that requires a sufficiently large bulk band gap, bifurcations in topological edge mode lasing can occur even when the band gap is maximized. We show that linear mode bifurcations from single-mode to multi-mode lasing can occur deep within the topological phase, sensitive to both the pump shape and lattice geometry. We suggest ways to suppress these bifurcations and preserve single-edge mode lasing.

中文翻译：

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二维拓扑激光器的边缘模式分叉。

拓扑激光器作为一种使用耦合谐振器阵列实现无序鲁棒单模激射的方法越来越受到关注。我们研究了二维耦合谐振器晶格中的激光，该二维共振器晶格在平凡和拓扑相位之间表现出跃迁，这使我们能够系统地表征整个拓扑相位的激光模式。我们表明，与需要足够大的体隙的常规拓扑鲁棒性不同，即使当带隙最大化时，拓扑边缘模式激射也会发生分叉。我们表明，从单模激光到多模激光的线性模分叉可能会在拓扑阶段的深处发生，对泵浦形状和晶格几何形状都敏感。我们建议了抑制这些分叉并保留单边模式激光的方法。