Suppression of parametric oscillatory instability in third generation gravitational wave detectors

TL;DR

This paper proposes a method to suppress parametric oscillatory instability in third-generation gravitational wave detectors by optimizing mirror radii of curvature, thereby reducing unstable optical modes through thermal lensing.

Contribution

It introduces a novel approach to mitigate nonlinear instability effects in advanced gravitational wave detectors by adjusting mirror curvatures to control optical mode stability.

Findings

Optimal mirror radii can significantly reduce unstable modes.

Thermal lensing effectively alters optical mode distributions.

Method enhances stability of next-generation detectors.

Abstract

We discuss one possible method for suppression of the nonlinear effect of a parametric oscillatory instability in a Fabry-Perot cavity of the next generation of gravitational wave detectors by determination of optimal radii of curvature of interferometers' mirrors. Varying the radii of curvature of the mirrors we can change the frequencies of the optical modes of the Fabry-Perot resonators and distributions of optical fields in optical modes, which, in turn, can change the number of unstable modes, leading to parametric oscillatory instability. The determination of the optimal values of the radii of curvature of mirrors to reduce the number of unstable modes by thermal lensing is fulfilled.