Progress in the measurement and reduction of thermal noise in optical coatings for gravitational-wave detectors
Résumé
Coating thermal noise is a fundamental limit for precision experiments based on optical and quantum transducers. In this review, after a brief overview of the techniques for coating thermal noise measurements, we present the latest worldwide research activity on low-noise coatings, with a focus on the results obtained at the Laboratoire des Matériaux Avancés. We report new updated values for the Ta2O5, Ta2O5−TiO2, and SiO2 coatings of the Advanced LIGO, Advanced Virgo, and KAGRA detectors, and new results from sputtered Nb2O5, TiO2−Nb2O5, Ta2O5−ZrO2, MgF2, AlF3, and silicon nitride coatings. Amorphous silicon, crystalline coatings, high-temperature deposition, multi-material coatings, and composite layers are also briefly discussed, together with the latest developments in structural analyses and models.
Mots clés
Amorphous materials
Extinction coefficients
Laser beams
Laser modes
Power spectral density
Refractive index
noise: thermal
gravitational radiation detector
transducer
surface
tantalum: oxygen
titanium: oxygen
silicon: oxygen
magnesium: fluorine
aluminum: fluorine
KAGRA
VIRGO
LIGO
measurement methods
performance
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