Broadband squeezing of quantum noise in a Michelson interferometer with Twin-Signal-Recycling

TL;DR

This paper reports the first experimental implementation of a Twin-Signal-Recycling Michelson interferometer with broadband quantum noise reduction achieved through squeezed light injection, enhancing sensitivity at a specific signal frequency.

Contribution

It demonstrates the first stable realization of TSR Michelson interferometer with broadband squeezing, confirming experimental results align with simulations.

Findings

Achieved up to 4 dB quantum noise reduction

Successfully locked and operated the interferometer

Validated experimental results with numerical simulations

Abstract

Twin-Signal-Recycling (TSR) builds on the resonance doublet of two optically coupled cavities and efficiently enhances the sensitivity of an interferometer at a dedicated signal frequency. We report on the first experimental realization of a Twin-Signal-Recycling Michelson interferometer and also its broadband enhancement by squeezed light injection. The complete setup was stably locked and a broadband quantum noise reduction of the interferometers shot noise by a factor of up to 4\,dB was demonstrated. The system was characterized by measuring its quantum noise spectra for several tunings of the TSR cavities. We found good agreement between the experimental results and numerical simulations.