Frequency combs induced by phase turbulence
Frequency combs induced by phase turbulence
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DOI：
10.1038/s41586-020-2386-6
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发表时间：
2020-06
期刊：
影响因子：
64.8
通讯作者：
M. Piccardo;B. Schwarz;D. Kazakov;Maximilian Beiser;N. Opačak;Yongrui Wang;S. Jha;J. Hillbrand-
中科院分区：
文献类型：
--
作者：
M. Piccardo;B. Schwarz;D. Kazakov;Maximilian Beiser;N. Opačak;Yongrui Wang;S. Jha;J. Hillbrand-
波浪不稳定性--在流体力学中引起湍流的过程--代表了由于非线性相互作用而使波浪中的小扰动的振幅增大的机制。在光子学中，波的不稳定性导致调制的光波形，其在相干锁定机制的存在下可以变成周期性的。这些周期性的光波形被称为光频梳。在环形微谐振梳中，由于谐振腔色散和组成晶体的克尔非线性之间的相互作用，注入的单色波变得不稳定。相比之下，在环形激光器中，不稳定性被认为只发生在极端的泵浦条件下。在这里，我们表明，尽管这个概念，半导体环形激光器的超快增益恢复，可以进入频率梳制度在低泵浦水平由于相位不稳定性，已知发生在流体力学，超导体和玻色-爱因斯坦凝聚。这种不稳定性源于线宽增强所提供的激光场的相位-振幅耦合，这产生了所需的色散和非线性效应的相互作用。我们制定的不稳定性条件的框架内的Ginzburg-Landau形式主义。我们观察到的本地化结构与耗散克尔孤子有几个相同的特性，这为连接半导体环形激光器和微谐振器频率梳迈出了第一步。
Wave instability—the process that gives rise to turbulence in hydrodynamics—represents the mechanism by which a small disturbance in a wave grows in amplitude owing to nonlinear interactions. In photonics, wave instabilities result in modulated light waveforms that can become periodic in the presence of coherent locking mechanisms. These periodic optical waveforms are known as optical frequency combs, –. In ring microresonator combs,, an injected monochromatic wave becomes destabilized by the interplay between the resonator dispersion and the Kerr nonlinearity of the constituent crystal. By contrast, in ring lasers instabilities are considered to occur only under extreme pumping conditions,. Here we show that, despite this notion, semiconductor ring lasers with ultrafast gain recovery,can enter frequency comb regimes at low pumping levels owing to phase turbulence—an instability known to occur in hydrodynamics, superconductors and Bose–Einstein condensates. This instability arises from the phase–amplitude coupling of the laser field provided by linewidth enhancement, which produces the needed interplay of dispersive and nonlinear effects. We formulate the instability condition in the framework of the Ginzburg–Landau formalism. The localized structures that we observe share several properties with dissipative Kerr solitons, providing a first step towards connecting semiconductor ring lasers and microresonator frequency combs.