Feedback Enhanced Sensitivity in Optomechanics: Surpassing the Parametric Instability Barrier

TL;DR

This paper demonstrates a feedback method to suppress parametric instability in optomechanical sensors, achieving over fivefold sensitivity enhancement beyond traditional limits.

Contribution

The authors introduce a feedback technique combining optomechanical transduction and electrical actuation to surpass the parametric instability barrier in micron-scale optomechanical systems.

Findings

Achieved 5.4-fold increase in sensitivity.

Final sensitivity reached 1.9×10⁻¹⁸ m Hz⁻¹/².

Successfully suppressed parametric instability effects.

Abstract

The intracavity power, and hence sensitivity, of optomechanical sensors is commonly limited by parametric instability. Here we characterize the parametric instability induced sensitivity degradation in a micron scale cavity optomechanical system. Feedback via optomechanical transduction and electrical gradient force actuation is applied to suppress the parametric instability. As a result a 5.4 fold increase in mechanical motion transduction sensitivity is achieved to a final value of $1.9\times 10^{-18}\rm m Hz^{-1/2}$.