Floquet phonon lasing in multimode optomechanical systems

TL;DR

This paper demonstrates that Floquet dynamics enable phase-locked multimode phonon lasing in a silicon nanocavity, leading to improved frequency stability and potential applications in stable, compact oscillators and coherent waveform synthesis.

Contribution

It introduces a method to achieve phase-locked multimode phonon lasing via Floquet dynamics in a multimode optomechanical system, which was not previously demonstrated.

Findings

Multimode phonon lasing can be phase-locked using Floquet dynamics.

Long-term frequency stability is significantly improved in multimode lasing.

The approach enables potential applications in stable, ultra-compact oscillators.

Abstract

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 phase-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 phase locking. These results provide a path towards highly stable ultra-compact oscillators, pulsed phonon lasing, coherent waveform synthesis, and emergent many-mode phenomena in oscillator arrays.