Demonstration of optical spring in an un-detuned cavity containing an optical parametric amplifier

TL;DR

This paper demonstrates how an optical parametric amplifier can enhance and tune the optical spring effect in an un-detuned cavity, with potential applications in gravitational wave detection.

Contribution

It introduces a novel method to manipulate the optical spring using an OPA within an un-detuned cavity, enabling dynamic tuning of the system.

Findings

Over 2x increase in optical spring frequency shift with OPA

Optical spring tunable by adjusting OPA phase

Potential application in gravitational wave detectors

Abstract

Here we demonstrate the capacity to manipulate the optical spring (OS) effect by employing an optical parametric amplifier (OPA) within an optical cavity. We observed more than a factor of 2 increase in the OS frequency shift with the OPA. We also showed for the first time that the OS can be tuned by solely adjusting the OPA phase and showing an un-detuned cavity exhibiting an optical spring. The method can be applied to gravitational wave detectors in the signal recycling configuration to realize narrow bandwidth high sensitivity. The OS can be tuned to align the detector peak sensitivity frequency to known frequency continuous gravitational wave signals, dynamically tuned to track the gravitational wave signal from merging compact binaries or tuned to search for the post-merger signal of known binary coalescence.