A5025428854- Pulsars and Gravitational Waves Research
- Advanced Frequency and Time Standards
- Geophysics and Sensor Technology
- High-pressure geophysics and materials
- Cold Atom Physics and Bose-Einstein Condensates
- Seismic Waves and Analysis
- Advanced Measurement and Metrology Techniques
- Advanced Fiber Laser Technologies
- Superconducting Materials and Applications
- Mechanical and Optical Resonators
- Experimental and Theoretical Physics Studies
- Advanced Fiber Optic Sensors
- Gamma-ray bursts and supernovae
- Superconducting and THz Device Technology
- Magnetic Properties and Applications
- Photorefractive and Nonlinear Optics
- Optical and Acousto-Optic Technologies
- Optical measurement and interference techniques
- Thermography and Photoacoustic Techniques
- Laser Material Processing Techniques
- Thermoelastic and Magnetoelastic Phenomena
- Fluid Dynamics and Turbulent Flows
- Astrophysics and Cosmic Phenomena
- Quantum Information and Cryptography
- Quantum Mechanics and Applications
Embry–Riddle Aeronautical University
2005-2023
University of Arizona
2018-2022
LIGO Scientific Collaboration
2003-2006
California Institute of Technology
2002-2005
Syracuse University
1999-2003
University of Glasgow
2002
Massachusetts Institute of Technology
2002
Stanford University
2002
Iowa State University
2002
We report on thermal noise from the internal friction of dielectric coatings made alternating layers Ta2O5 and SiO2 deposited fused silica substrates. present calculations in gravitational wave interferometers due to optical coatings, when material properties coating are different those substrate mechanical loss angle is anisotropic. The for strains parallel surface was determined ringdown experiments. measured quality factor three samples with them. coated found be (4.2 +- 0.3)*10^(-4)...
Current interferometric gravitational wave detectors use test masses with mirror coatings formed from multiple layers of dielectric materials, most commonly alternating SiO2 (silica) and Ta2O5 (tantala). However, mechanical loss in the Ta2O5/SiO2 may limit design sensitivity for advanced detectors. We have investigated sources coatings, including associated coating-substrate interface, coating-layer interfaces, bulk material. Our results indicate that is coating materials substantially...
Thermal noise arising from mechanical dissipation in dielectric reflective coatings is expected to critically limit the sensitivity of precision measurement systems such as high-resolution optical spectroscopy, frequency standards and future generations interferometric gravitational wave detectors. We present measurements effect post-deposition heat treatment on temperature dependence ion-beam sputtered tantalum pentoxide between 11 K 300 K. find that strongly dependent at which was carried...
In this Perspective we summarize the status of technological development for large-area and low-noise substrate-transferred GaAs/AlGaAs (AlGaAs) crystalline coatings interferometric gravitational-wave (GW) detectors. These topics were originally presented in a workshop{\dag} bringing together members GW community from laser interferometer observatory (LIGO), Virgo, KAGRA collaborations, along with scientists precision optical metrology community, industry partners extensive expertise...
The displacement noise in the test-mass mirrors of interferometric gravitational wave detectors is proportional to their elastic dissipation at observation frequencies. In this paper, we analyze one fundamental source thin coatings, thermoelastic damping associated with dissimilar thermal and properties film substrate. We obtain expressions for factor necessary interpret resonant loss measurements, spectral density imposed on a Gaussian beam reflected from face coated mass. predicted size...
Interferometric gravitational wave detectors use mirrors whose substrates are formed from materials of low intrinsic mechanical dissipation. The two most likely choices for the test masses in future advanced fused silica or sapphire (Rowan S et al 2000 Phys. Lett. A 265 5). These must be coated to form mirrors, highly reflecting at 1064 nm. We have measured excess losses associated with adding dielectric coatings and calculated effect loss on thermal noise an interferometer.
Here we report the first results comparing temperature dependence of mechanical dissipation in thin films Ta_2O_5 and doped with TiO_2, a type suitable for use multilayer optical coatings advanced gravitational wave detectors. The indicate that doping TiO_2 can significantly alter distribution activation energies associated low-temperature peak.
All current gravitational wave detectors use test masses coated with alternating layers of two different dielectric materials to form highly reflective mirrors. The thermal noise from mechanical dissipation associated such coatings may be significant for future as advanced LIGO. We have measured the a number types formed SiO2 (silica) and Ta2O5 (tantala). frequency dependence has been determined, taking into account contribution thermoelastic loss.
Thermal noise arising from mechanical dissipation in oxide coatings is a major limitation to many precision measurement systems, including optical frequency standards, high-resolution spectroscopy and interferometric gravity wave detectors. Presented here are measurements of as function temperature between 7 K 290 ion-beam-sputtered Ta2O5 doped with TiO2, showing loss peak at 20 K. Analysis the provides first evidence source coatings, leading possibilities for reduction thermal effects.
To determine the dissipation induced by surface of fused silica fibers, we measured quality factor fibers having various diameters. We a maximum 21 million and extrapolated to obtain an intrinsic for 30 million. Dissipation in dominated at diameters less than about 1 mm. developed method characterizing surface-induced that is independent sample geometry or mode shape.
We calculate the thermal noise in half-infinite mirrors containing a layer of arbitrary thickness and depth made excessively lossy material but with same elastic properties as substrate. For special case thin on surface mirror, excess scales ratio coating loss to substrate laser beam spot size. Assuming silica function 3x10-8 must be less than 3x10-5 for 6 cm size 7 micrometers thick avoid increasing spectral density displacement by more 10%. A similar number is obtained sapphire test masses.
Abstract We report on the development and extensive characterization of co-sputtered tantala–zirconia (Ta 2 O 5 -ZrO ) thin films, with goal to decrease coating Brownian noise in present future gravitational-wave detectors. tested a variety sputtering processes different energies deposition rates, we considered effect values cation ratio η = Zr/(Zr + Ta) post-deposition heat treatment temperature T optical mechanical properties films. Co-sputtered zirconia proved be an efficient way...
We have measured the mechanical dissipation in a sample of fused silica drawn into rod. The was hung from multiple-bob suspension, which isolated it rubbing against its support, recoil support structure, and seismic noise. quality factor, Q, for several modes with high value 57 million found mode number 2 at 726 Hz. This result is about factor higher than previous room temperature measurements. Q strongly dependent on handling, pristine flame-polished surface yielding 3-4 times had been...
The use of fused-silica ribbons as suspensions in gravitational wave interferometers can result significant improvements pendulum mode thermal noise. Surface loss sets a lower bound to the level noise achievable, at what depends on dissipation depth and other physical parameters. For LIGO II, high breaking strength pristine fused silica filaments, correct choice ribbon aspect ratio (to minimize thermoelastic damping), low combined with achievable parameters reduce suspension well below...
Low mechanical loss, high index-of-refraction thin-film coating materials are of particular interest to the gravitational wave detection community, where reduced mirror thermal noise in detectors is desirable. Current studies focused on understanding loss amorphous metal oxides such as SiO2, Ta2O5 and HfO2. Here, we report recent measurements temperature dependence ion-beam sputtered hafnium dioxide (HfO2) coatings that have undergone heat treatment. The results indicate that, even when...
We report on a high-resolution wave-front sensor that measures the complete spatial profile of any frequency component laser field containing multiple frequencies. This probe technique was developed to address necessity measuring overlap carrier with each sideband exiting output port gravitational-wave interferometer. present results an experimental test probe, where we were able construct single radio-frequency at level -50 dBc.
We report on mechanical loss associated with hydroxy-catalysis (or ‘silicate’) bonding between fused silica substrates in the presence of potassium hydroxide or sodium silicate. measured quality factor three samples, each composed two half-rods bonded together their flat surfaces and compared them to that an unbonded half-rod. The measurements show a significant reduction due silicate bonds. calculate region ϕbond estimate effect thermal noise Advanced LIGO interferometers will be small.
Interferometric gravitational wave detectors use mirrors whose substrates are formed from materials of low intrinsic mechanical dissipation. The two most likely choices for the test masses in future advanced fused silica or sapphire. These must be coated to form mirrors, highly reflecting at 1064nm. We have measured excess losses associated with adding dielectric coatings and calculate effect loss on thermal noise an interferometer.
We investigate the possibility of observing very low frequency (VLF) electromagnetic radiation produced from vacuum by gravitational waves. review calculations leading to conversion waves into and show how this process evades well-known prohibition against particle production Using Newman-Penrose scalars, we estimate luminosity proposed counterpart coming neutron star oscillations. The detection would provide an indirect way with future spacecraft missions, especially lunar orbiting probes.
Thermal noise arising from mechanical dissipation in oxide coatings is a major limitation to many precision measurement systems, including optical frequency standards, high resolution spectroscopy and interferometric gravity wave detectors. Presented here are measurements of as function temperature between 7 K 290 ion-beam sputtered Ta2O5 doped with TiO2, showing loss peak at 20 K. Analysis the provides first evidence source coatings, leading possibilities for reduction thermal effects.
Thermo-optic noise is likely to be the dominant source in next generation ultralow optical cavities. We developed three measurement and analysis methods, allowing us estimate level of coating thermo-optic cavities, including interferometric gravitational wave detectors. measured shift broadband transmission spectra as a function temperature for single-layer, high index coatings order find coefficient, ${\ensuremath{\beta}}_{H}$, while assuming thermal expansion ${\ensuremath{\alpha}}_{H}$....
Research on the projective measurement of gravitons increasingly supports Dysons conclusions that detection single is not physically possible. It therefore prudent to consider alternative signatures non-classicality in gravitational wave detections determine if gravity quantized. Coincident multiple detector operations make it possible bipartite measurement-induced entanglement, process, as a signature non-classicality. By developing model based fixed number for system, we demonstrate...