Measurement of radiation-pressure-induced optomechanical dynamics in a suspended Fabry-Perot cavity

TL;DR

This paper experimentally investigates radiation-pressure effects in a high-power optical cavity, revealing an optical spring and parametric instability relevant for advanced gravitational wave detectors and quantum measurement technologies.

Contribution

It provides the first detailed measurement of optical rigidity and parametric instability in a suspended Fabry-Perot cavity, advancing understanding of optomechanical interactions.

Findings

Measured optical rigidity of 3×10^4 N/m

Observed parametric instability with R=3

Demonstrated effects relevant for GW detectors

Abstract

We report on experimental observation of radiation-pressure induced effects in a high-power optical cavity. These effects play an important role in next generation gravitational wave (GW) detectors, as well as in quantum non-demolition (QND) interferometers. We measure the properties of an optical spring, created by coupling of an intense laser field to the pendulum mode of a suspended mirror; and also the parametric instability (PI) that arises from the nonlinear coupling between acoustic modes of the cavity mirrors and the cavity optical mode. Specifically, we measure an optical rigidity of $K = 3 \times 10^4$ N/m, and PI value $R = 3$.