A. Mullavey
A5067287373- Pulsars and Gravitational Waves Research
- Geophysics and Gravity Measurements
- Geophysics and Sensor Technology
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Advanced Frequency and Time Standards
- Mechanical and Optical Resonators
- Statistical and numerical algorithms
- Cosmology and Gravitation Theories
- Seismic Waves and Analysis
- Astronomical Observations and Instrumentation
- Advanced Fiber Laser Technologies
- Magnetic confinement fusion research
- Cold Atom Physics and Bose-Einstein Condensates
- Astrophysics and Cosmic Phenomena
- High-pressure geophysics and materials
- Atomic and Subatomic Physics Research
- Advanced MEMS and NEMS Technologies
- Radio Astronomy Observations and Technology
- Adaptive optics and wavefront sensing
- Experimental and Theoretical Physics Studies
- Particle Accelerators and Free-Electron Lasers
- Mechanics and Biomechanics Studies
- Black Holes and Theoretical Physics
- Superconducting Materials and Applications
LIGO Scientific Collaboration
2016-2025
Louisiana State University
2013-2014
Australian National University
2008-2013
Cardiff University
2011
Carleton College
2011
California Institute of Technology
2011
Andrews University
2011
Charles Sturt University
2011
Quantum (Australia)
2011
The Laser Interferometer Gravitational Wave Observatory (LIGO) has been directly detecting gravitational waves from compact binary mergers since 2015. We report on the first use of squeezed vacuum states in direct measurement with Advanced LIGO H1 and L1 detectors. This achievement is culmination decades research to implement gravitational-wave During ongoing O3 observation run, are improving sensitivity interferometers signals above 50 Hz by up 3 dB, thereby increasing expected detection...
Quantum noise imposes a fundamental limitation on the sensitivity of interferometric gravitational-wave detectors like LIGO, manifesting as shot and quantum radiation pressure noise. Here, we present first realization frequency-dependent squeezing in full-scale detectors, resulting reduction both noise, with broadband detector enhancement from tens hertz to several kilohertz. In LIGO Hanford detector, reduced amplitude by factor 1.6 (4.0 dB) near 1 kHz; Livingston was 1.9 (5.8 dB). These...
Parametric instabilities have long been studied as a potentially limiting effect in high-power interferometric gravitational wave detectors. Until now, however, these never observed kilometer-scale interferometer. In this work we describe the first observation of parametric instability an Advanced LIGO detector, and means by which it has removed barrier to progress.
The motion of a mechanical object, even human-sized should be governed by the rules quantum mechanics. Coaxing them into state is, however, difficult because thermal environment masks any signature object's motion. also effects proposed modifications mechanics at large mass scales. We prepared center-of-mass 10-kilogram oscillator in with an average phonon occupation 10.8. reduction temperature, from room temperature to 77 nanokelvin, is commensurate 11 orders-of-magnitude suppression...
Interferometric gravitational-wave detectors are complex instruments comprised of a Michelson interferometer enhanced by multiple coupled cavities. Active feedback control is required to operate these and keep the cavities locked on resonance. The optical response highly nonlinear until good operating point reached. linear range between 1% fringe for each degree freedom. resonance lock has be achieved in all five degrees freedom simultaneously, making acquisition difficult. Furthermore,...
The advanced LIGO gravitational wave detectors are nearing their design sensitivity and should begin taking meaningful astrophysical data in the fall of 2015. These resonant optical interferometers will have unprecedented to strains caused by passing waves. input optics play a significant part allowing these devices reach such sensitivities. Residing between pre-stabilized laser main interferometer, subsystem is tasked with preparing beam for interferometry at sub-attometer level while...
A series of recent articles have presented results demonstrating optical cooling macroscopic objects, highlighting the importance this phenomenon for investigations quantum mechanics and its implications thermal noise in gravitational wave detectors. In Letter, we present a measurement off-resonance suspension 1 g oscillator, show that it can be cooled to just 70 mK. The is achieved by using servo impose phase delay between oscillator motion force. model developed how rigidity...
The Advanced Laser Interferometer Gravitational-wave Observatory (LIGO) detectors have completed their initial upgrade phase and will enter the first observing run in late 2015, with detector sensitivity expected to improve future runs. Through combined efforts of on-site commissioners Detector Characterization group LIGO Scientific Collaboration, interferometer performance, terms data quality, at both observatories has vastly improved from start commissioning present. already surpassed...
Interferometric gravitational wave detectors operate with high optical power in their arms order to achieve shot-noise limited strain sensitivity. A significant limitation increasing the is phenomenon of three-mode parametric instabilities, which laser field arm cavities scattered into higher-order modes by acoustic cavity mirrors. The can further drive via radiation pressure, potentially producing an exponential buildup. One proposed technique stabilize instability active damping modes. We...
Residual motion of the arm cavity mirrors is expected to prove one principal impediments systematic lock acquisition in advanced gravitational-wave interferometers. We present a technique which overcomes this problem by employing auxiliary lasers at twice fundamental measurement frequency pre-stabilise cavities' lengths. Applying approach, we reduce apparent length noise 1.3 m long, independently suspended Fabry-Perot 30 pm rms and successfully transfer longitudinal control system from laser laser.
Squeezed light has become a standard technique to enhance the sensitivity of gravitational wave detectors. Both optical losses and phase noise in squeezed path can degrade achievable improvements. Phase be mitigated by having high bandwidth servo stabilize squeezer from interferometer. In advanced LIGO, this control loop is limited 4 km arm cavity free spectral range about ~15 kHz. Future generation gravitational-wave detectors are designed employ much longer cavities. For cosmic explorer...
We describe the design of a small optic suspension system, referred to as tip-tilt mirror suspension, used isolate selected optics for interferometer sensing and control beams in advanced LIGO gravitational wave detectors. The suspended are isolated all 6 degrees freedom, with eigenmode frequencies between 1.3 Hz 10 Hz. has voice-coil actuators which provide an angular range ±4 mrad pitch yaw freedom.
We present a technique for the stable transfer of an optical frequency reference over kilometer-scale fiber link. This implements phase measurements and laser feedback to cancel out fluctuations that are introduced standard as it passes through fiber. also results bench top experiment, developed Advanced LIGO lock acquisition system, where this is implemented phase-lock two Nd:YAG lasers, 4.6 km The resulting differential noise reaches level low 0.5 mHz/ radical Hz Fourier frequencies...
We present measurements of the frequency dependence thermal noise in aluminum and niobium flexures. Our cover audio-frequency band from 10 Hz to kHz, which is particular relevance ground-based interferometric gravitational wave detectors, span up an order magnitude above below fundamental flexure resonances. Results two flexures are well explained by a simple model both structural thermoelastic loss play role. The ability such explain this interplay important for investigations...
We present the first demonstration of real-time closed-loop control and deterministic tuning an independently suspended Fabry-Perot optical cavity using digitally enhanced heterodyne interferometry, realizing a peak sensitivity ~10 pm/√Hz over 10-1000 Hz frequency band. The methods presented are readily extensible to multiple coupled cavities. As such, we anticipate that refinements this technique may find application in future interferometric gravitational-wave detectors.
We present measurements of thermal noise in niobium and aluminium flexures. Our cover the audio frequency band from 10Hz to 10kHz, which is particular relevance ground-based interferometric gravitational wave detectors, span up an order magnitude above below fundamental flexure resonances at 50Hz - 300Hz. results are well-explained by a simple model both structural thermoelastic loss play role. The ability such explain this interplay important for investigations quantum-radiation-pressure...
In this experiment, we actively manipulate the phase and magnitude of feedback system which is used to lock a resonant cavity pre-stabilised laser. By doing so, can freely modify effective optical spring study in damping and/or regimes.
The LIGO detectors are a technological marvel, the culmination of ~50 years research and development, that have opened up new window on universe by making first detections gravitational waves. can measure strain caused wave perturbations down to 10-23 (at their most sensitive frequency band). In this talk, I will give an overview techniques allowed us reach such incredible precision, where possible relate said field acoustics.