Amorphous optical coatings of present gravitational-wave interferometers

Abstract

We report on the results of an extensive campaign of optical and mechanical characterization of the ion-beam sputtered oxide layers (Ta${}_2$O${}_5$, TiO${}_2$, Ta${}_2$O${}_5$-TiO${}_2$, SiO${}_2$) within the high-reflection coatings of the Advanced LIGO, Advanced Virgo and KAGRA gravitational-wave detectors: refractive index, thickness, optical absorption, composition, density, internal friction and elastic constants have been measured; the impact of deposition rate and post-deposition annealing on coating internal friction has been assessed. For Ta${}_2$O${}_5$ and SiO${}_2$ layers, coating internal friction increases with the deposition rate, whereas the annealing treatment either erases or largely reduces the gap between samples with different deposition history. For Ta${}_2$O${}_5$-TiO${}_2$ layers, the reduction of internal friction due to TiO${}_2$ doping becomes effective only if coupled with annealing. All measured samples showed a weak dependence of internal friction on frequency (${\varphi }_c(f)=a{f}^b$, with $-0.208<b<0.140$ depending on the coating material considered). SiO${}_2$ films showed a mode-dependent loss branching, likely due to spurious losses at the coated edge of the samples. The reference loss values of the Advanced LIGO and Advanced Virgo input (ITM) and end (ETM) mirror HR coatings have been updated by using our estimated value of Young's modulus of Ta${}_2$O${}_5$-TiO${}_2$ layers (120 GPa) and are about 10\% higher than previous estimations.

References in corpus (28)

• Observation of Gravitational Waves from a Binary Black Hole Merger
• GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral
• Cavity Optomechanics
• Advanced Virgo: a 2nd generation interferometric gravitational wave detector
• Multi-messenger Observations of a Binary Neutron Star Merger
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• Advanced LIGO
• Exploring the Sensitivity of Next Generation Gravitational Wave Detectors
• Sensitivity Studies for Third-Generation Gravitational Wave Observatories
• Interferometer design of the KAGRA gravitational wave detector
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• Mechanical loss in state-of-the-art amorphous optical coatings
• Effect of heat treatment on mechanical dissipation in Ta${}_2$O${}_5$ coatings
• Measurement of Thermal Noise in Multilayer Coatings with Optimized Layer Thickness
• Measurements of a low temperature mechanical dissipation peak in a single layer of Ta2O5 doped with TiO2
• Progress in the measurement and reduction of thermal noise in optical coatings for gravitational-wave detectors
• Direct Measurement of Coating Thermal Noise in Optical Resonators
• High-Reflection Coatings for Gravitational-Wave Detectors: State of The Art and Future Developments
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• Material loss angles from direct measurements of broadband thermal noise
• Investigation of the Young's modulus and thermal expansion of amorphous titania-doped tantala films

Cited by in corpus (30)

• Sensitivity and Performance of the Advanced LIGO Detectors in the Third Observing Run
• Advanced LIGO detector performance in the fourth observing run
• Low mechanical loss TiO${}_2$:GeO${}_2$ coatings for reduced thermal noise in Gravitational Wave Interferometers
• Observation of a Correlation Between Internal friction and Urbach Energy in Amorphous Oxides Thin Films
• Structure and morphology of low mechanical loss TiO${}_2$-doped Ta${}_2$O${}_5$
• Comprehensive study of amorphous metal oxide and Ta${}_2$O${}_5$-based mixed oxide coatings for gravitational-wave detectors
• Optical and mechanical properties of ion-beam-sputtered Nb${}_2$O${}_5$ and TiO${}_2$-Nb${}_2$O${}_5$ thin films for gravitational-wave interferometers
• Exploration of co-sputtered Ta${}_2$O${}_5$-ZrO${}_2$ thin films for gravitational-wave detectors
• Prediction of crystallized phases of amorphous Ta${}_2$O${}_5$-based mixed oxide thin films using density functional theory calculations
• Optical and mechanical properties of ion-beam-sputtered MgF${}_2$ thin films for gravitational-wave interferometers
• Effects of mixing and annealing on the optical and mechanical properties of TiO${}_2$:Ta${}_2$O${}_5$ amorphous coatings
• Development of ion-beam sputtered silicon nitride thin films for low-noise mirror coatings of gravitational-wave detectors
• Measurements of Optical Scatter Versus Annealing Temperature for Amorphous Ta2O5 and TiO2:Ta2O5 Thin Films
• Imaging Scatterometer for Observing In-Situ Changes to Optical Coatings During Air Annealing
• Study on electro-optic noise in crystalline coatings toward future gravitational wave detectors
• Determination of compressive stress in thin films using micro-machined buckled membranes
• Mirror Surface Nanostructuring via Laser Direct Writing -- Characterization and Physical Origins
• Towards optomechanical parametric instabilities prediction in ground-based gravitational wave detectors
• Strategies to reduce the thermoelastic loss of multimaterial coated finite substrates
• Optimizing Gravitational-Wave Detector Design for Squeezed Light
• Deep insights into the local structure of amorphous Ta2O5 thin films by X-ray pair distribution function analysis
• Linking fluctuation and dissipation in spatially extended out-of-equilibrium systems
• Characterization of ion-beam-sputtered AlF${}_3$ thin films for gravitational-wave interferometers
• Mechanical loss and stability analysis of NEXCERA in ultra-stable optical cavities
• A Systematic Error in the Internal Friction Measurement of Coatings for Gravitational Waves Detectors
• Thermal Noise Reduction in Ternary Optical Coatings: From Ti::GeO${}_2$-Based Ternary Systems to High Index Materials
• Connected Network Model for the Mechanical Loss of Amorphous Materials
• Resolving features and derivatives in noisy data using weighted Whittaker-Henderson smoothing
• Comparative Analysis of Thermal Models for Test Masses in Next-Generation Gravitational Wave Interferometers
• Polarization Dependence of Excess Loss of Amorphous Coating Supermirror in Optical Region for Cavity Ringdown Spectroscopy