Progress in the measurement and reduction of thermal noise in optical coatings for gravitational-wave detectors

2019/12/31 by M. Granata, Massimo Granata, Alex Amato +19
Physics and Astronomy · #Advanced Frequency and Time Standards #Amorphous solid #Coating #Cosmology and Gravitation Theories #Detector #Noise (video) #Noise reduction #Optical coating #Pulsars and Gravitational Waves Research #Silicon #Silicon nitride #Thermal #physics.ins-det #physics.optics

paper · pdf · doi:10.1364/ao.377293

published as Appl. Opt. 59 (2020) A229 · arXiv admin note: text overlap with arXiv:1909.03737

openalex publication_date 2020/01/10 · arxiv created 2020/01/21 · openalex created_date 2020/01/23 · arxiv updated 2022/03/25 · openalex updated_date 2026/08/05

Abstract

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 world-wide 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 of structural analyses and models.

Citations

• Amorphous optical coatings of present gravitational-wave interferometers
• Thermal noise reduction and absorption optimization via multimaterial coatings
• Advanced Virgo: a 2nd generation interferometric gravitational wave detector
• Multimaterial coatings with reduced thermal noise
• A “gentle” nodal suspension for measurements of the acoustic attenuation in materials
• 1.5 μm lasers with sub 10 mHz linewidth
• Cavity Optomechanics