Mitigation of Parametric Instability

TL;DR

This paper discusses the challenge of parametric instability in high-power gravitational wave detectors and presents an experimental approach using auxiliary laser radiation pressure for active mitigation.

Contribution

It introduces a novel active mitigation system for parametric instability based on radiation pressure from an auxiliary laser, with initial experimental results.

Findings

Initial experimental results demonstrate the feasibility of the mitigation system.

The proposed system offers a flexible approach to control parametric instability.

The paper summarizes existing mitigation techniques and explains the working principle of the new system.

Abstract

A key action for enhancing the sensitivity of gravitational wave (GW) detectors based on laser interferometry is to increase the laser power. However, in such a high-power regime, a nonlinear optomechanical phenomenon called parametric instability (PI) leads to the amplification of the mirrors vibrational modes preventing the detector functioning. Thus this phenomenon limits the detectors maximum power and so its performances. Our group has started an experimental research program aiming at realizing a exible and active mitigation system, based on the radiation pressure applied by an auxiliary laser. A summary on the PI mitigation techniques will be presented, we will explain the working principle of the system that we are implementing and report about the first experimental results.