Observation of Kerr soliton microcomb locked with a phonon laser

Cavity optomechanics and dissipative Kerr soliton microcomb are two research fields that followed the parallel lines of development, and the interplay of their respective elements was unseen in the past. Here, we present an observation of mutually synchronized Kerr soliton microcomb and optomechanical oscillation in the same microresonator. We generated a previously unknown type of breathing soliton to drive the mechanical mode of the microresonator into a forced oscillation at the breathing frequency. Once the breathing frequency is tuned close to the mechanical frequency of the system, the breathing soliton and the excited mechanical oscillation suddenly lock together into a synchronization. This state locks to an almost unchanged breathing frequency, and exists over a considerable frequency range of the pump laser. The locked breathing Kerr soliton can substantially lower its phase noise and improve its long-term stability, providing potential applications in various areas.