Reducing the mirrors coating noise in laser gravitational-wave antennae by means of double mirrors

TL;DR

This paper proposes using short anti-resonant Fabry-Perot cavities as additional mirrors to significantly reduce coating noise in laser gravitational-wave detectors, improving their sensitivity.

Contribution

It introduces a novel method of replacing end mirrors with anti-resonant cavities to lower coating noise in gravitational-wave antennae.

Findings

Coating fluctuations contribute significantly to noise in current detectors.

Using anti-resonant cavities can reduce coating noise substantially.

The method offers a promising approach to enhance gravitational-wave detection sensitivity.

Abstract

Recent researches show that the fluctuations of the dielectric mirrors coating thickness can introduce a substantial part of the future laser gravitational-wave antennae total noise budget. These fluctuations are especially large in the high-reflectivity end mirrors of the Fabry-Perot cavities which are being used in the laser gravitational-wave antennae. We show here that the influence of these fluctuations can be substantially decreased by using additional short Fabry-Perot cavities, tuned in anti-resonance instead of the end mirrors.