Breathers are localized structures that undergo a periodic oscillation in their duration and amplitude. Optical microresonators, benefiting from their high-quality factor, provide an ideal test bench for studying breathing phenomena. In a monochromatically pumped microresonator system, intrinsic breathing instabilities are widely observed in the form of temporal dissipative Kerr solitons which only exist in the effectively red-detuned regime. Here, we demonstrate a novel bichromatic pumping scheme to create compulsive breathing microcombs via respectively distributing two pump lasers at the effectively blue- and red-detuned sides of a single resonance. We experimentally discover the artificial cnoidal wave breathers and molecular crystal-like breathers in a photonic chip-based silicon nitride microresonator and theoretically describe their intriguing temporal dynamics based on the bichromatic pumping Lugiato–Lefever equation. In particular, the corresponding breathing microcombs exhibit diverse comb line spacing ranging from 2 to 17 times the free spectral range of the microresonator. Our discovery not only provides a simple yet robust method to harness microcombs with reconfigurable comb line spacing but also reveals a new class of breathing waves in driven dissipative nonlinear systems.

中文翻译：

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光学微谐振器中的双色泵浦人工椭圆曲线呼吸器


呼吸器是局部结构，其持续时间和幅度会经历周期性振荡。光学微谐振器凭借其高品质因数，为研究呼吸现象提供了理想的测试平台。在单色泵浦微谐振器系统中，内在呼吸不稳定性以时间耗散克尔孤子的形式被广泛观察到，其仅存在于有效红失谐状态中。在这里，我们展示了一种新颖的双色泵浦方案，通过将两个泵浦激光器分别分布在单个共振的有效蓝色和红色失谐侧来创建强制呼吸微梳。我们通过实验在基于光子芯片的氮化硅微谐振器中发现了人工椭圆形波呼吸器和类分子晶体呼吸器，并基于双色泵浦 Lugiato-Lefever 方程从理论上描述了它们有趣的时间动力学。特别是，相应的呼吸微梳表现出不同的梳线间距，范围为微谐振器自由光谱范围的 2 至 17 倍。我们的发现不仅提供了一种简单而强大的方法来利用具有可重构梳线间距的微梳，而且还揭示了驱动耗散非线性系统中的一类新的呼吸波。