Squeezing quadrature rotation in the acoustic band via optomechanics

TL;DR

This paper explores using optomechanical squeezing to enhance gravitational-wave interferometer sensitivity by enabling frequency-dependent quadrature rotation, potentially surpassing fixed-quadrature squeezing advantages, despite challenges with excess noise.

Contribution

It demonstrates the potential of optomechanical squeezing to produce frequency-dependent quadrature rotation for gravitational-wave detection, offering a novel approach to surpass the standard quantum limit.

Findings

Optomechanical squeezing can produce quadrature rotation over the gravitational-wave spectrum.

Frequency-dependent squeezing offers detection advantages over fixed-quadrature methods.

Excess noise near mechanical resonance poses a significant challenge.

Abstract

We examine the use of optomechanically-generated squeezing to obtain a sensitivity enhancement for interferometers in the gravitational-wave band. The intrinsic dispersion characteristics of optomechanical squeezing around the mechanical frequency are able to produce squeezing at different quadratures over the spectrum, a feature required by gravitational-wave interferometers to beat the standard quantum limit over an extended frequency range. Under realistic assumptions we show that the amount of available squeezing and the intrinsic quadrature rotation may provide, compared to similar amounts of fixed-quadrature squeezing, a detection advantage. A significant challenge for this scheme, however, is the amount of excess noise that is generated in the unsqueezed quadrature at frequencies near the mechanical resonance.