Opt Express. 2023 Mar 13;31(6):9264-9274. doi: 10.1364/OE.482828.
The coherent dynamics in networks of coupled oscillators is of great interest in wave-physics since the coupling produces various dynamical effects, such as coherent energy exchange (beats) between the oscillators. However, it is common wisdom that these coherent dynamics are transients that quickly decay in active oscillators (e.g. lasers) since pump saturation causes mode competition that results, for homogeneous gain, in the prevalence of the single winning mode. We observe that pump saturation in coupled parametric oscillators counter-intuitively encourages the multi-mode dynamics of beating and indefinitely preserves it, despite the existence of mode competition. We explore in detail the coherent dynamics of a pair of coupled parametric oscillators with a shared pump and arbitrary coupling in a radio frequency (RF) experiment, as well as in simulation. Specifically, we realize two parametric oscillators as different frequency-modes of a single RF cavity and couple them arbitrarily using a digital high-bandwidth FPGA. We observe persistent coherent beats that are maintained at any pump level, even high above the threshold. The simulation highlights how the interplay of pump depletion between the two oscillators prevents them from synchronizing, even when the oscillation is deeply saturated.
在波物理学中，耦合振荡器网络中的相干动力学非常有趣，因为耦合会产生各种动力学效应，例如振荡器之间的相干能量交换（拍频）。然而，人们普遍认为，这些相干动力学是瞬态的，在活跃的振荡器（例如激光器）中很快就会衰减，因为泵浦饱和会导致模式竞争，从而导致在均匀增益下，单一获胜模式占主导地位。我们观察到，在耦合参量振荡器中，泵浦饱和反直觉地鼓励了拍频的多模动力学，并在存在模式竞争的情况下无限期地保持了这种动力学。我们在射频 (RF) 实验以及模拟中详细研究了具有共享泵浦和任意耦合的一对耦合参量振荡器的相干动力学。具体来说，我们将两个参量振荡器实现为单个 RF 腔的不同频率模式，并使用数字高带宽 FPGA 任意耦合它们。我们观察到持续的相干拍频，即使在泵浦水平很高的情况下，也能保持稳定。模拟突出了两个振荡器之间的泵浦损耗相互作用如何阻止它们即使在深度饱和时也同步。
