Stable double-resonance optical spring in laser gravitational-wave detectors

TL;DR

This paper investigates the stability and potential advantages of a double-resonance optical spring in laser gravitational-wave detectors, showing it can surpass quantum limits and be tested in prototype interferometers.

Contribution

It introduces a simple stability criterion for double-resonance optical springs and demonstrates their feasibility in prototype interferometers for future gravitational wave detection.

Findings

Double resonance occurs when optical spring and detuning frequencies coincide.

Stable double resonance can surpass the Standard Quantum Limit.

Prototype interferometers can demonstrate stable double resonance.

Abstract

We analyze the optical spring characteristics of a double pumped Fabry-Perot cavity. A double-resonance optical spring occurs when the optical spring frequency and the detuning frequency of the cavity coincide. We formulate a simple criterion for the stability of an optical spring and apply it to the double resonance regime. Double resonance configurations are very promising for future gravitational wave detectors as they allow us to surpass the Standard Quantum Limit. We show that stable double resonance can be demonstrated in middle scale prototype interferometers such as the Glasgow 10m-Prototype, Gingin High Optical Power Test Facility or the AEI 10m Prototype Interferometer before being implemented in future gravitational wave detectors.