Back-action amplification and quantum limits in optomechanical measurements

TL;DR

This paper demonstrates a technique to surpass the Standard Quantum Limit in optomechanical measurements by amplifying signals through radiation-pressure back-action in a detuned cavity, advancing quantum measurement sensitivity.

Contribution

It provides the first experimental demonstration of signal amplification via back-action in a detuned cavity to go beyond the SQL in optomechanical sensing.

Findings

Successfully amplified signals beyond the SQL

Demonstrated radiation-pressure back-action as a quantum-limited amplification method

Enhanced sensitivity in optomechanical displacement measurements

Abstract

Optical interferometry is by far the most sensitive displacement measurement technique available, with sensitivities at the 10^-20 m/rootHz level in the large-scale gravitational-wave interferometers currently in operation. Second generation interferometers will experience a 10-fold improvement in sensitivity and be mainly limited by quantum noise, close to the Standard Quantum Limit (SQL), once considered as the ultimate displacement sensitivity achievable by interferometry. In this Letter, we experimentally demonstrate one of the techniques envisioned to go beyond the SQL: amplification of a signal by radiation-pressure back-action in a detuned cavity.