Dissipative Kerr solitons are localized structures that exist in nonlinear optical cavities. They lead to the formation of microcombs—chip-scale frequency combs that could facilitate precision frequency synthesis and metrology by capitalizing on advances in silicon photonics. Previous demonstrations have mainly focused on anomalous dispersion cavities. Notwithstanding, localized structures also exist in the normal dispersion regime in the form of circulating dark pulses, but their physical dynamics is far from being understood. Here, we explore dark-pulse Kerr combs generated in normal dispersion optical microresonators and report the discovery of reversible switching between coherent dark-pulse combs, whereby distinct states can be accessed deterministically. Furthermore, we reveal that the formation of dark-pulse Kerr combs is associated with the appearance of another resonance, a feature that has never been observed for dark pulses and is ascribed to soliton behavior. These results contribute to understanding the nonlinear physics in normal dispersion nonlinear cavities and provide insight into the generation of microcombs with high conversion efficiency.

中文翻译：

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光学微谐振器中暗脉冲Kerr频率梳状态的切换动力学

耗散克尔孤子是存在于非线性光学腔中的局部结构。它们导致了微梳的形成，即芯片级的频率梳，可以利用硅光子学的进步来促进精确的频率合成和计量。先前的演示主要集中在异常色散腔上。尽管如此，局部结构也以循环暗脉冲的形式存在于正常色散状态下，但其物理动力学还远未弄清。在这里，我们研究了正常色散光学微谐振器中产生的暗脉冲克尔梳，并报告了相干暗脉冲梳之间可逆切换的发现，从而可以确定地访问不同的状态。此外，我们揭示了暗脉冲克尔梳的形成与另一个共振的出现有关，这种现象从未在暗脉冲中观察到，并且归因于孤子行为。这些结果有助于理解正态色散非线性腔体中的非线性物理，并有助于洞察具有高转换效率的微梳的产生。