Thermoelastic-damping noise from sapphire mirrors in a fundamental-noise-limited interferometer

TL;DR

This paper presents the first high-precision measurements of thermal noise in large sapphire mirrors used in interferometers, confirming theoretical predictions and informing gravitational wave detector sensitivity.

Contribution

It provides the first broadband measurements of thermoelastic-damping noise in sapphire mirrors, validating existing theoretical models.

Findings

Measurements agree with theoretical predictions

Thermoelastic-damping noise limits the sensitivity

Implications for gravitational wave detection sensitivity

Abstract

We report the first high-precision interferometer using large sapphire mirrors, and we present the first direct, broadband measurements of the fundamental thermal noise in these mirrors. Our results agree well with the thermoelastic-damping noise predictions of Braginsky, et al. [Phys. Lett. A 264, 1(1999)] and Cerdonio, et al.[Phys. Rev. D 63, 082003 (2001)], which have been used to predict the astrophysical reach of advanced interferometric gravitational wave detectors.