It is a well-known phenomenon that a self-sustained oscillator can be synchronized to a weak external signal if the frequency of the latter is near the natural frequency of the former. There are many diverse examples of such unidirectional mechanism in our everyday life, such as the circadian rhythms of cells originating from the rotation of the Earth around its axis and around the Sun or the working principle of a radio-controlled watch. In this work, with the participation of MIND group they study an optically-driven oscillator taking place in a silicon optomechanical crystal cavity and its synchronization to an external harmonic signal that modulates the driving laser. They demonstrate a giant phase-locking bandwidth exceeding 60% of the natural frequency of the oscillator, which greatly overcomes other approaches exploiting external locking.
Giant injection-locking bandwidth of a self-pulsing limit-cycle in an optomechanical cavity. Daniel Navarro-Urrios, Guillermo Arregui, Martín F. Colombano, Juliana Jaramillo-Fernández, Alessandro Pitanti, Amadeu Griol, Laura Mercadé, Alejandro Martínez & Néstor E. Capuj. Communication Physics 5, 330 (2022).