Mercadé Laura, Pelka Karl, Burgwal Roel, Xuereb André, Martínez Alejandro, Verhagen Ewold
Nanophotonics Technology Center, Universitat Politècnica de Valencia, Camino de Vera s/n, 46022 Valencia, Spain.
Department of Physics, University of Malta, Msida MSD 2080, Malta.
Phys Rev Lett. 2021 Aug 13;127(7):073601. doi: 10.1103/PhysRevLett.127.073601.
Dynamical radiation pressure effects in cavity optomechanical systems give rise to self-sustained oscillations or 'phonon lasing' behavior, producing stable oscillators up to GHz frequencies in nanoscale devices. Like in photonic lasers, phonon lasing normally occurs in a single mechanical mode. We show here that mode-locked, multimode phonon lasing can be established in a multimode optomechanical system through Floquet dynamics induced by a temporally modulated laser drive. We demonstrate this concept in a suitably engineered silicon photonic nanocavity coupled to multiple GHz-frequency mechanical modes. We find that the long-term frequency stability is significantly improved in the multimode lasing state as a result of the mode locking. These results provide a path toward highly stable ultracompact oscillators, pulsed phonon lasing, coherent waveform synthesis, and emergent many-mode phenomena in oscillator arrays.
腔光机械系统中的动态辐射压力效应会引发自持振荡或“声子激光”行为，在纳米级器件中产生高达吉赫兹频率的稳定振荡器。与光子激光器类似，声子激光通常在单一机械模式中出现。我们在此表明，通过由时间调制激光驱动引起的弗洛凯动力学，可以在多模光机械系统中建立锁模多模声子激光。我们在一个与多个吉赫兹频率机械模式耦合的经过适当设计的硅光子纳米腔中演示了这一概念。我们发现，由于锁模，多模激光状态下的长期频率稳定性得到了显著提高。这些结果为实现高度稳定的超紧凑型振荡器、脉冲声子激光、相干波形合成以及振荡器阵列中出现的多模现象提供了一条途径。
