Optomechanical synchronization across multi-octave frequency spans

Caique C Rodrigues,Michal Lipson,Gustavo S Wiederhecker,Cauê M Kersul,Thiago P Mayer Alegre,André G Primo

doi:10.1038/s41467-021-25884-x

Caique C Rodrigues, Michal Lipson + Show 4 more

Open Access

https://doi.org/10.1038/s41467-021-25884-x

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Abstract

Experimental exploration of synchronization in scalable oscillator microsystems has unfolded a deeper understanding of networks, collective phenomena, and signal processing. Cavity optomechanical devices have played an important role in this scenario, with the perspective of bridging optical and radio frequencies through nonlinear classical and quantum synchronization concepts. In its simplest form, synchronization occurs when an oscillator is entrained by a signal with frequency nearby the oscillator’s tone, and becomes increasingly challenging as their frequency detuning increases. Here, we experimentally demonstrate entrainment of a silicon-nitride optomechanical oscillator driven up to the fourth harmonic of its 32 MHz fundamental frequency. Exploring this effect, we also experimentally demonstrate a purely optomechanical RF frequency divider, where we performed frequency division up to a 4:1 ratio, i.e., from 128 MHz to 32 MHz. Further developments could harness these effects towards frequency synthesizers, phase-sensitive amplification and nonlinear sensing.

Highlights

Experimental exploration of synchronization in scalable oscillator microsystems has unfolded a deeper understanding of networks, collective phenomena, and signal processing
With the recent convergence among optical, mechanical and electrical waves using scalable microfabrication technologies, synchronization has emerged as a powerful tool targeted at technological applications, such as phase-lock loops in radio-based communications[6,7,8], and at developing the fundamentals of chaotic systems[9], injection locking[10,11,12], electro and optomechanical devices[13,14,15,16,17,18,19,20], nonlinear dynamics[21,22,23,24,25,26], network coupling[27,28,29,30], and quantum synchronization[31,32,33,34,35,36]
The Lorentzian shape of the optical resonance provides a unique route to tailor the degree of nonlinearity of the optical force, defining how different harmonics of the mechanical oscillation are excited during the opticalto-mechanical transduction

Summary

Introduction

Experimental exploration of synchronization in scalable oscillator microsystems has unfolded a deeper understanding of networks, collective phenomena, and signal processing. The time-traces in Fig. 2d–g are captured with the injection signal frequency being precisely matched to each harmonic using a RF power of −10 dBm. As the RF driving frequency is detuned from each harmonic, the OMO response is monitored through the RF spectrum centered around the fundamental frequency Ω0/ 2π, as shown in the density plots of Fig. 2h–k.

Results

Conclusion