Fundamental quantum limits of multi-carrier optomechanical sensors

TL;DR

This paper investigates the quantum limits of multi-carrier optomechanical sensors, such as gravitational wave detectors, and finds that single-carrier configurations achieve optimal sensitivity, which is already attainable with current LIGO technology.

Contribution

The study demonstrates that multi-carrier optomechanical sensors do not surpass single-carrier sensors in quantum-limited sensitivity, providing insights into optimal sensor design.

Findings

Single-carrier sensors achieve optimal quantum-limited sensitivity.

Current LIGO systems already reach this optimal precision.

Multi-carrier interactions do not improve sensitivity beyond single-carrier configurations.

Abstract

Optomechanical sensors involving multiple optical carriers can experience mechanically mediated interactions causing multi-mode correlations across the optical fields. One instance is laser-interferometric gravitational wave detectors which introduce multiple carrier frequencies for classical sensing and control purposes. An outstanding question is whether such multi-carrier optomechanical sensors outperform their single-carrier counterpart in terms of quantum-limited sensitivity. We show that the best precision is achieved by a single-carrier instance of the sensor. For the current LIGO detection system this precision is already reachable.