A5065768993- Pulsars and Gravitational Waves Research
- Gamma-ray bursts and supernovae
- Geophysics and Gravity Measurements
- Astrophysical Phenomena and Observations
- Cosmology and Gravitation Theories
- High-pressure geophysics and materials
- Astrophysics and Cosmic Phenomena
- Seismic Waves and Analysis
- Geophysics and Sensor Technology
- Atomic and Subatomic Physics Research
- Statistical and numerical algorithms
- Radio Astronomy Observations and Technology
- Cold Atom Physics and Bose-Einstein Condensates
- Dark Matter and Cosmic Phenomena
- Mechanical and Optical Resonators
- Magnetic confinement fusion research
- earthquake and tectonic studies
- Advanced Fiber Laser Technologies
- Astronomical Observations and Instrumentation
- Advanced Frequency and Time Standards
- Adaptive optics and wavefront sensing
- Coastal and Marine Dynamics
- Radiology practices and education
- Acoustic Wave Resonator Technologies
- Ocean Waves and Remote Sensing
University of Glasgow
2019-2024
University of Arizona
2022
Embry–Riddle Aeronautical University
2022
American University
2016-2021
Thermal noise associated with the mechanical loss of current highly reflective mirror coatings is a critical limit to sensitivity gravitational-wave detectors. Several alternative coating materials show potential for reducing thermal noise, but cannot be used due their high optical absorption. Multimaterial have been proposed enable use such reduce while minimizing impact on total absorption coating. Here we present experimental verification multimaterial concept, by integrating aSi into...
We investigated elastic loss in GaAs/AlGaAs multilayers to help determine the suitability of these coatings for future gravitational wave detectors. measured large ($\approx 70$-mm diameter) substrate-transferred crystalline coating samples with an improved substrate polish and bonding method. The loss, when decomposed into bulk shear contributions, was shown arise entirely from $\phi_{\mathrm{Bulk}} = (5.33 \pm 0.03)\times 10^{-4}$, $\phi_{\mathrm{Shear}} (0.0 5.2) \times 10^{-7}$. These...
Precision interferometry is the leading method for extremely sensitive measurements in gravitational wave astronomy.Thermal noise of dielectric coatings poses a limitation to sensitivity these interferometers.To decrease coating thermal noise, new crystalline GaAs/AlGaAs multilayer mirrors have been developed.To date, surface figure and thickness uniformity alternative low-loss has not investigated.Surface errors, example, cause small angle scattering thereby limit an interferometer.Here we...
Mirrors made of silicon have been proposed for use in future cryogenic gravitational-wave detectors, which will be significantly more sensitive than current room-temperature detectors. These mirrors are planned to diameters $\ensuremath{\approx}50$ cm and a mass $\ensuremath{\approx}200$ kg. While single-crystalline float-zone meets the requirements low optical absorption mechanical loss, production this type material is restricted sizes much smaller required. Here we present studies...
Substrate-transferred, 70-mm diameter AlGaAs coatings were tested for possible use in gravitational wave detectors by measuring the elastic loss [ϕbulk = (5.33±0.03)×10−4 and ϕ s h e a r 0.0 − + 5.2 × 10 7] excess from bonding defects [≈ 5%].
We report on the persistence of mechanical loss with time ion beam sputtered dielectric coatings made from alternating layers Ta_2O_5 and SiO_2 deposited onto fused silica substrates. From this, we predict coating thermal noise in gravitational wave interferometers, after coated optics have been stored for years. measured modal quality factor, Q, two samples 2015. These also had their Q's 2002. conclude that storing disks 13 years does not change thus storage Advanced LIGO detector until...
The elastic loss of ~70-mm diameter substrate-transferred crystalline coatings was measured via mechanical ringdown. angles, decomposed into bulk and shear components, (5.33±0.03)×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-4</sup> <; 5.2)×10 xmlns:xlink="http://www.w3.org/1999/xlink">-7</sup> respectively, were incorporated in a finite element model to predict the performance 35-mm long cavity with 250-μm beam waist (radius), yielding...
The standard approach for predicting thermal noise in optical mirrors using the fluctuation-dissipation theorem requires knowledge of level all significant sources mechanical loss occurring at oscillation amplitudes noise. Using a gentle nodal suspension system read out by Michelson interferometer, we tested amplitude-dependence $\mathrm{GaAs}/{\mathrm{Al}}_{0.92}{\mathrm{Ga}}_{0.08}\mathrm{As}$ multilayer coatings on silica substrates range from just above rms amplitude up to typical...