Thermal noises and noise compensation in high-reflection multilayer coating

TL;DR

This paper investigates thermal noise sources in high-reflection mirror coatings and proposes simple modifications to reduce phase noise, enhancing the stability of high-Q optical cavities used in precision measurements.

Contribution

It introduces a method for suppressing thermal phase noise in multilayer coatings through simple alterations, improving mirror stability in sensitive optical systems.

Findings

Thermal fluctuations cause significant phase noise in optical mirror coatings.

Simple coating modifications can effectively reduce thermorefractive and thermoelastic noise.

Enhanced mirror stability benefits high-precision optical applications like gravitational wave detection.

Abstract

Thermal fluctuations of different origin in the substrate and in the coating of optical mirrors produce phase noise in the reflected wave. This noise determines the ultimate stabilization capability of high-Q cavities used as a reference system. In particular this noise is significant in interferometric laser gravitational wave antennas. It is shown that simple alteration of a mirror multilayer coating may provide suppression of phase noise produced by thermorefractive, thermoelastic, photothermal and thermoradiation induced fluctuations in the coating.