A large-scale single-mode array laser based on a topological edge mode
A large-scale single-mode array laser based on a topological edge mode
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DOI：
10.1515/nanoph-2021-0608
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发表时间：
2021-08
期刊：
影响因子：
7.5
通讯作者：
Natsuko Ishida;Y. Ota;Wenbo Lin;T. Byrnes;Y. Arakawa;S. Iwamoto
中科院分区：
文献类型：
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作者：
Natsuko Ishida;Y. Ota;Wenbo Lin;T. Byrnes;Y. Arakawa;S. Iwamoto
拓扑激光器作为稳健性单模激光器的有力候选已经得到了广泛的研究。典型的拓扑激光器采用单模拓扑边缘态，在设计的拓扑带隙中确定性地出现，对无序具有鲁棒性。这些特性似乎在追求能够单模操作的高功率激光器方面具有很高的吸引力。本文从理论上分析了基于拓扑边缘态的大尺度单模激光器。我们考虑了一个由几百个谐振腔组成的大型阵列激光器，它支持广泛分布在谐振腔之间的单一拓扑边缘模式。我们使用紧密结合近似建立了描述激光器的基本模型，并基于第一激光边缘模式和第二激光竞争体模式之间的阈值增益差Δα来评估单模激光的稳定性。我们的计算表明，更强的腔间耦合和更低的损耗有利于实现器件的稳定运行。当假设谐振腔和其他实际参数之间的平均耦合为100 cm−1时，阈值增益差Δα可以达到约2 cm−1，这将足以使用传统的半导体激光器结构实现稳定的单模激光。我们还考虑了可能的障碍和远程相互作用的影响，以评估非理想情况下激光的鲁棒性。这些结果为单模高功率拓扑激光器的发展奠定了基础。
Abstract Topological lasers have been intensively investigated as a strong candidate for robust single-mode lasers. A typical topological laser employs a single-mode topological edge state, which appears deterministically in a designed topological bandgap and exhibits robustness to disorder. These properties seem to be highly attractive in pursuit of high-power lasers capable of single mode operation. In this paper, we theoretically analyze a large-scale single-mode laser based on a topological edge state. We consider a sizable array laser consisting of a few hundreds of site resonators, which support a single topological edge mode broadly distributed among the resonators. We build a basic model describing the laser using the tight binding approximation and evaluate the stability of single mode lasing based on the threshold gain difference Δα between the first-lasing edge mode and the second-lasing competing bulk mode. Our calculations demonstrate that stronger couplings between the cavities and lower losses are advantageous for achieving stable operation of the device. When assuming an average coupling of 100 cm−1 between site resonators and other realistic parameters, the threshold gain difference Δα can reach about 2 cm−1, which would be sufficient for stable single mode lasing using a conventional semiconductor laser architecture. We also consider the effects of possible disorders and long-range interactions to assess the robustness of the laser under non-ideal situations. These results lay the groundwork for developing single-mode high-power topological lasers.