Squeezing a thermal mechanical oscillator by stabilized parametric effect on the optical spring

TL;DR

This paper demonstrates a method to squeeze a thermal mechanical oscillator below the zero-point motion using stabilized parametric modulation of the optical spring, surpassing traditional noise reduction limits.

Contribution

It introduces a stabilized parametric feedback scheme that enhances mechanical squeezing beyond -3dB, achieving -7.4dB noise reduction in an optomechanical system.

Findings

Achieved -7.4dB squeezing of a mechanical oscillator.

Surpassed the -3dB limit of parametric resonance.

Effective for macroscopic systems in moderate cooling.

Abstract

We report the confinement of an optomechanical micro-oscillator in a squeezed thermal state, obtained by parametric modulation of the optical spring. We propose and implement an experimental scheme based on parametric feedback control of the oscillator, which stabilizes the amplified quadrature while leaving the orthogonal one unaffected. This technique allows us to surpass the -3dB limit in the noise reduction, associated to parametric resonance, with a best experimental result of -7.4dB. In a moderately cooled system, our technique can be efficiently exploited to produce strong squeezing of a macroscopic mechanical oscillator below the zero-point motion.