All-optical coherent quantum-noise cancellation in cascaded optomechanical systems

TL;DR

This paper demonstrates how cascading an all-optical negative mass oscillator with an optomechanical sensor enhances quantum noise cancellation, surpassing the standard quantum limit with improved modular design and practical implementation insights.

Contribution

It introduces a cascaded all-optical CQNC scheme with analysis of arrangements, showing advantages of placing the negative mass oscillator before the sensor for realistic setups.

Findings

Cascaded scheme achieves sub-SQL sensitivity.

Placing negative mass oscillator first is optimal.

Modular design improves control and performance.

Abstract

Coherent quantum noise cancellation (CQNC) can be used in optomechanical sensors to surpass the standard quantum limit (SQL). In this paper, we investigate an optomechanical force sensor that uses the CQNC strategy by cascading the optomechanical system with an all-optical effective negative mass oscillator. Specifically, we analyze matching conditions, losses and compare the two possible arrangements in which either the optomechanical or the negative mass system couples first to light. While both of these orderings yield a sub-SQL performance, we find that placing the effective negative mass oscillator before the optomechanical sensor will always be advantageous for realistic parameters. The modular design of the cascaded scheme allows for better control of the sub-systems by avoiding undesirable coupling between system components, while maintaining similar performance to the integrated configuration proposed earlier. We conclude our work with a case study of a micro-optomechanical implementation.