Squeezing at the normal-mode splitting frequency of a nonlinear coupled cavity

TL;DR

This paper reports the first experimental demonstration of quantum noise squeezing in a nonlinear coupled-cavity system, achieving significant noise reduction at the normal-mode splitting frequency, with implications for quantum sensing and detection.

Contribution

It introduces the first experimental realization of squeezing in a coupled-cavity system with nonlinear materials, validating theoretical models and analyzing performance limitations.

Findings

Achieved 3.3 dB quantum noise reduction.

Demonstrated squeezing at 7.47 MHz normal-mode splitting frequency.

Validated theoretical predictions with experimental data.

Abstract

Coupled optical cavities, which support normal modes, play a critical role in optical filtering, sensing, slow-light generation, and quantum state manipulation. Recent theoretical work has proposed incorporating nonlinear materials into these systems to enable novel quantum technologies. Here, we report the first experimental demonstration of squeezing generated in a quantum-enhanced coupled-cavity system, achieving a quantum noise reduction of 3.3 dB around the normal-mode splitting frequency of 7.47 MHz. We provide a comprehensive analysis of the system's loss mechanisms and performance limitations, validating theoretical predictions. Our results underscore the promise of coupled-cavity squeezers for advanced quantum applications, including gravitational wave detection and precision sensing.