We propose a system that exploits the fundamental features of topological photonics and synthetic dimensions to force many semiconductor laser resonators to synchronize, mutually lock, and under suitable modulation emit a train of transform-limited mode-locked pulses. These lasers exploit the Floquet topological edge states in a 1D array of ring resonators, which corresponds to a 2D topological system with one spatial dimension and one synthetic frequency dimension. We show that the lasing state of the multi-element laser system possesses the distinct characteristics of spatial topological edge states while exhibiting topologically protected transport. The topological synthetic-space edge mode imposes a constant-phase difference between the multi-frequency modes on the edges, and together with modulation of the individual elements forces the ensemble of resonators to mode-lock and emit short pulses, robust to disorder in the multi-resonator system. Our results offer a proof-of-concept mechanism to actively mode-lock a laser diode array of many lasing elements, which is otherwise extremely difficult due to the presence of many spatial modes of the array. The topological synthetic-space concepts proposed here offer an avenue to overcome this major technological challenge, and open new opportunities in laser physics.

中文翻译：

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利用合成尺寸的锁模拓扑绝缘体激光器

我们提出了一种利用拓扑光子学和合成尺寸的基本特征来迫使许多半导体激光谐振器进行同步，相互锁定并在适当的调制下发出一系列变换限制的锁模脉冲的系统。这些激光器利用环形谐振器的一维阵列中的Floquet拓扑边缘状态，该状态对应于具有一个空间维和一个合成频率维的2D拓扑系统。我们表明，多元素激光系统的激射态具有空间拓扑边缘态的独特特征，同时表现出拓扑受保护的传输。拓扑合成空间边缘模式在边缘的多频模式之间施加了恒定的相位差，并与各个元件的调制一起迫使谐振器进行锁模并发射短脉冲，这对多谐振器系统中的无序干扰很强。我们的结果提供了一种概念验证机制来主动锁模许多激光元件的激光二极管阵列，否则由于存在阵列的许多空间模式，因此这极其困难。本文提出的拓扑合成空间概念为克服这一重大技术挑战提供了途径，并为激光物理学开辟了新的机遇。