ORCID Profile
0000-0001-5825-2401
Current Organisation
University of Western Australia
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Astronomical and Space Sciences | General Relativity and Gravitational Waves | Classical and Physical Optics | Quantum Optics | Instruments And Techniques | Physical Sciences Not Elsewhere Classified | Astronomical and Space Instrumentation | Seismology and Seismic Exploration | Astronomical sciences | Photonics and Electro-Optical Engineering (excl. Communications) | Quantum Physics | Optical Physics | Space instrumentation | Electrical and Electronic Engineering | Precision Engineering | Astronomical and Space Sciences not elsewhere classified | Optical Technology | Cosmology and extragalactic astronomy | Lasers and quantum electronics | Optical Physics Not Elsewhere Classified | General relativity and gravitational waves | Lasers and Quantum Electronics | Quantum Optics And Lasers
Expanding Knowledge in the Physical Sciences | Expanding Knowledge in Technology | Scientific Instruments | Expanding Knowledge in Engineering | Higher education | Physical sciences | Scientific instrumentation | Expanding Knowledge in the Information and Computing Sciences |
Publisher: IOP Publishing
Date: 21-04-2005
Publisher: American Astronomical Society
Date: 19-03-2020
Abstract: On 2019 April 25, the LIGO Livingston detector observed a compact binary coalescence with signal-to-noise ratio 12.9. The Virgo detector was also taking data that did not contribute to detection due to a low signal-to-noise ratio, but were used for subsequent parameter estimation. The 90% credible intervals for the component masses range from to ( – if we restrict the dimensionless component spin magnitudes to be smaller than 0.05). These mass parameters are consistent with the in idual binary components being neutron stars. However, both the source-frame chirp mass and the total mass of this system are significantly larger than those of any other known binary neutron star (BNS) system. The possibility that one or both binary components of the system are black holes cannot be ruled out from gravitational-wave data. We discuss possible origins of the system based on its inconsistency with the known Galactic BNS population. Under the assumption that the signal was produced by a BNS coalescence, the local rate of neutron star mergers is updated to 250–2810 .
Publisher: SPIE
Date: 20-12-2019
DOI: 10.1117/12.2542601
Publisher: IOP Publishing
Date: 12-12-2008
Publisher: IOP Publishing
Date: 02-05-2018
Publisher: AIP Publishing
Date: 23-02-2009
DOI: 10.1063/1.3088850
Abstract: We have observed negative optical torsional rigidity in an 80 m suspended high optical power cavity that would induce the Sidles–Sigg instability as a result of sufficient circulating power. The magnitude of the negative optical spring constant per unit power is a few μN m/W as the result of the optical torsional stiffness in the yaw mode of a suspended mirror Fabry–Pérot cavity. It has been observed to depend on the g-factor of the cavity which is in agreement with the Sidles–Sigg theory.
Publisher: American Physical Society (APS)
Date: 04-09-2019
Publisher: American Physical Society (APS)
Date: 31-05-2019
Publisher: American Physical Society (APS)
Date: 16-01-2008
Publisher: American Physical Society (APS)
Date: 05-08-2015
Publisher: American Physical Society (APS)
Date: 30-09-2019
Publisher: IOP Publishing
Date: 02-03-2006
Publisher: IOP Publishing
Date: 16-10-2009
Publisher: IOP Publishing
Date: 24-03-2022
Abstract: Parametric instability (PI), induced by the interaction between the cavity optical modes and acoustic modes of a mirror, is an inherent risk in interferometric gravitational wave detectors. The instability can result in exponential growth in acoustic mode litude and the saturation of detectors control systems. In this paper we analyse PI in the neutron star extreme matter observatory, a proposed high optical power (4.5 MW) detector, operating at cryogenic temperatures with silicon test masses (TMs), targeting high sensitivity between 1 and 4 kHz. Our results show that with current design parameters, approximately 16 unstable modes will arise per TM with maximum parametric gain ∼10. Varying the TM radius of curvature from the nominal values could eliminate PI, however not with current manufacture or actuator capability. PI mitigation will be required to suppress all unstable modes. This analysis identifies four optical modes and 16 acoustic modes dominating PI in NEMO paves the way for the design of PI mitigation strategies.
Publisher: American Astronomical Society
Date: 30-09-2019
Abstract: When formed through dynamical interactions, stellar-mass binary black holes (BBHs) may retain eccentric orbits ( e 0.1 at 10 Hz) detectable by ground-based gravitational-wave detectors. Eccentricity can therefore be used to differentiate dynamically formed binaries from isolated BBH mergers. Current template-based gravitational-wave searches do not use waveform models associated with eccentric orbits, rendering the search less efficient for eccentric binary systems. Here we present the results of a search for BBH mergers that inspiral in eccentric orbits using data from the first and second observing runs (O1 and O2) of Advanced LIGO and Advanced Virgo. We carried out the search with the coherent WaveBurst algorithm, which uses minimal assumptions on the signal morphology and does not rely on binary waveform templates. We show that it is sensitive to binary mergers with a detection range that is weakly dependent on eccentricity for all bound systems. Our search did not identify any new binary merger candidates. We interpret these results in light of eccentric binary formation models. We rule out formation channels with rates ≳100 Gpc −3 yr −1 for e 0.1, assuming a black hole mass spectrum with a power-law index ≲2.
Publisher: Elsevier BV
Date: 08-2010
Publisher: American Astronomical Society
Date: 11-09-2019
Publisher: Elsevier BV
Date: 09-2011
Publisher: Optica Publishing Group
Date: 13-07-2021
DOI: 10.1364/OE.430276
Abstract: Optical loss plays a significant role in optical experiments involving optical cavities such as recycling cavities and filter cavities in laser interferometer gravitational-wave detectors. For those cavities, modal frequency degeneracy, where the fundamental and a higher order mode resonate inside the cavity simultaneously, is a potential mechanism which may bring extra optical loss to the cavity thus degrade detection sensitivity. In this paper, we report observation of modal frequency degeneracy in a large-scale suspended Fabry-Pérot cavity. The cavity g -factor is tuned by a CO 2 laser heating one test mass, and the cavity finesse is obtained from a ring-down measurement of the transmitted light. We demonstrate that the modal frequency degeneracy can cause a reduction of the cavity finesse by up to ∼30%, corresponding to a ∼2-fold increase in total optical loss. To minimize optical loss in gravitational-wave detectors, the effect of modal frequency degeneracy needs to be taken into account in the design and operation of the detector.
Publisher: The Optical Society
Date: 07-01-2009
DOI: 10.1364/AO.48.000355
Abstract: Wavefront distortion due to absorption in the substrates and coatings of mirrors in advanced gravitational wave interferometers has the potential to compromise the operation and sensitivity of these interferometers [Opt. Lett.29, 2635-2637 (2004)]. We report the first direct spatially-resolved measurement, to our knowledge, of such wavefront distortion in a high optical power cavity. The measurement was made using an ultrahigh sensitivity Hartmann wavefront sensor on a dedicated test facility. The sensitivity of the sensor was lambda/730, where lambda=800 nm.
Publisher: IOP Publishing
Date: 17-09-2010
Publisher: American Physical Society (APS)
Date: 16-03-2011
Publisher: American Physical Society (APS)
Date: 23-11-2021
Publisher: AIP Publishing
Date: 06-2021
DOI: 10.1063/5.0047069
Abstract: We present a low frequency rotational accelerometer coined ALFRA with a few nrad/Hz readout sensitivity above 20 mHz and 0.1 nrad/Hz above 50 mHz. The ALFRA is a beam-balance style rotation sensor, which pivots about a cross flexure designed to allow mounting with any orientation, the axis of the pivot determining which rotational component is measured. The high sensitivity is achieved through the use of a walk-off sensor readout used in a feedback loop with an electromagnetic coil to keep the beam dynamically locked. The ALFRA is relatively compact for a ground rotation sensor, measuring at 780 × 240 × 55 mm3.
Publisher: IOP Publishing
Date: 02-03-2006
Publisher: American Physical Society (APS)
Date: 24-08-2020
Publisher: Springer Science and Business Media LLC
Date: 09-2005
Publisher: Wiley
Date: 04-10-2016
Publisher: Elsevier BV
Date: 06-2005
Publisher: American Physical Society (APS)
Date: 25-01-2010
Publisher: AIP Publishing
Date: 06-02-2023
DOI: 10.1063/5.0136869
Abstract: Excellent mechanical and thermal properties of silicon make it a promising material for the test masses in future gravitational wave detectors. However, the birefringence of silicon test masses, due to impurity and residual stress during crystal growth or external stress, can reduce the interference contrast in an interferometer. Using the polarization–modulation approach and a scanning system, we mapped the birefringence of a float zone silicon test mass in the ⟨100⟩ crystal orientation to assess the suitability of such material for future gravitational wave detectors. Apart from the stress-induced birefringence at the supporting area due to the weight of the test mass, the high resolution birefringence map of the silicon test mass revealed a high birefringence feature in the test mass. At the central 40 mm area, birefringence is in the range of mid 10−9 to low 10−8, which satisfy the requirement for future gravitational wave detectors.
Publisher: American Astronomical Society
Date: 07-04-2017
Publisher: American Physical Society (APS)
Date: 10-03-2008
Publisher: IOP Publishing
Date: 22-10-2020
Abstract: Microresonators with high Q -factor are essential components for optomechanical experiments. Here we report on the development of ‘cat-flap’ micro-pendulums consisting of sub-millimetre scale micromirrors supported by nanometre-thickness flexures. The micromirror pendulum is designed to achieve the lowest possible flexure stiffness, which enables maximal dilution of mechanical losses through the use of optical springs. An angular spring constant of 1 × 10 − 9 N ⋅ m/radian , corresponding to a fundamental frequency (in the absence of gravity) of 18 Hz has been demonstrated. It is shown that Q -factors up to 10 8 at an optical spring frequency of 25 kHz could be achieved with these pendulums. By extrapolating the measurement results to a s le with a double thickness mirror pad, we estimate that it may be possible to achieve a Q -factor of 5 × 10 8 at 100 kHz at room temperature.
Publisher: American Physical Society (APS)
Date: 10-03-2008
Publisher: American Physical Society (APS)
Date: 10-03-2008
Publisher: Cambridge University Press (CUP)
Date: 2020
DOI: 10.1017/PASA.2020.39
Abstract: Gravitational waves from coalescing neutron stars encode information about nuclear matter at extreme densities, inaccessible by laboratory experiments. The late inspiral is influenced by the presence of tides, which depend on the neutron star equation of state. Neutron star mergers are expected to often produce rapidly rotating remnant neutron stars that emit gravitational waves. These will provide clues to the extremely hot post-merger environment. This signature of nuclear matter in gravitational waves contains most information in the 2–4 kHz frequency band, which is outside of the most sensitive band of current detectors. We present the design concept and science case for a Neutron Star Extreme Matter Observatory (NEMO): a gravitational-wave interferometer optimised to study nuclear physics with merging neutron stars. The concept uses high-circulating laser power, quantum squeezing, and a detector topology specifically designed to achieve the high-frequency sensitivity necessary to probe nuclear matter using gravitational waves. Above 1 kHz, the proposed strain sensitivity is comparable to full third-generation detectors at a fraction of the cost. Such sensitivity changes expected event rates for detection of post-merger remnants from approximately one per few decades with two A+ detectors to a few per year and potentially allow for the first gravitational-wave observations of supernovae, isolated neutron stars, and other exotica.
Publisher: American Physical Society (APS)
Date: 10-03-2008
Publisher: Springer Science and Business Media LLC
Date: 28-09-2020
DOI: 10.1007/S41114-020-00026-9
Abstract: We present our current best estimate of the plausible observing scenarios for the Advanced LIGO, Advanced Virgo and KAGRA gravitational-wave detectors over the next several years, with the intention of providing information to facilitate planning for multi-messenger astronomy with gravitational waves. We estimate the sensitivity of the network to transient gravitational-wave signals for the third (O3), fourth (O4) and fifth observing (O5) runs, including the planned upgrades of the Advanced LIGO and Advanced Virgo detectors. We study the capability of the network to determine the sky location of the source for gravitational-wave signals from the inspiral of binary systems of compact objects, that is binary neutron star, neutron star–black hole, and binary black hole systems. The ability to localize the sources is given as a sky-area probability, luminosity distance, and comoving volume. The median sky localization area (90% credible region) is expected to be a few hundreds of square degrees for all types of binary systems during O3 with the Advanced LIGO and Virgo (HLV) network. The median sky localization area will improve to a few tens of square degrees during O4 with the Advanced LIGO, Virgo, and KAGRA (HLVK) network. During O3, the median localization volume (90% credible region) is expected to be on the order of $$10^{5}, 10^{6}, 10^{7}\\mathrm {\\ Mpc}^3$$ 10 5 , 10 6 , 10 7 Mpc 3 for binary neutron star, neutron star–black hole, and binary black hole systems, respectively. The localization volume in O4 is expected to be about a factor two smaller than in O3. We predict a detection count of $$1^{+12}_{-1}$$ 1 - 1 + 12 ( $$10^{+52}_{-10}$$ 10 - 10 + 52 ) for binary neutron star mergers, of $$0^{+19}_{-0}$$ 0 - 0 + 19 ( $$1^{+91}_{-1}$$ 1 - 1 + 91 ) for neutron star–black hole mergers, and $$17^{+22}_{-11}$$ 17 - 11 + 22 ( $$79^{+89}_{-44}$$ 79 - 44 + 89 ) for binary black hole mergers in a one-calendar-year observing run of the HLV network during O3 (HLVK network during O4). We evaluate sensitivity and localization expectations for unmodeled signal searches, including the search for intermediate mass black hole binary mergers.
Publisher: IOP Publishing
Date: 12-02-2004
Publisher: American Physical Society (APS)
Date: 11-11-2021
Publisher: Springer Science and Business Media LLC
Date: 26-04-2018
DOI: 10.1007/S41114-018-0012-9
Abstract: We present possible observing scenarios for the Advanced LIGO, Advanced Virgo and KAGRA gravitational-wave detectors over the next decade, with the intention of providing information to the astronomy community to facilitate planning for multi-messenger astronomy with gravitational waves. We estimate the sensitivity of the network to transient gravitational-wave signals, and study the capability of the network to determine the sky location of the source. We report our findings for gravitational-wave transients, with particular focus on gravitational-wave signals from the inspiral of binary neutron star systems, which are the most promising targets for multi-messenger astronomy. The ability to localize the sources of the detected signals depends on the geographical distribution of the detectors and their relative sensitivity, and $$90\\%$$ 90 % credible regions can be as large as thousands of square degrees when only two sensitive detectors are operational. Determining the sky position of a significant fraction of detected signals to areas of 5– $$20~\\mathrm {deg}^2$$ 20 deg 2 requires at least three detectors of sensitivity within a factor of $$\\sim 2$$ ∼ 2 of each other and with a broad frequency bandwidth. When all detectors, including KAGRA and the third LIGO detector in India, reach design sensitivity, a significant fraction of gravitational-wave signals will be localized to a few square degrees by gravitational-wave observations alone.
Publisher: AIP Publishing
Date: 07-1998
DOI: 10.1063/1.1149014
Abstract: In this article we report the successful locking and operation of an 8 m Michelson interferometer which uses multistage cantilever spring vibration isolators. The control system for normal mode d ing is described. The performance and dominant noise sources of this interferometer are discussed.
Publisher: IOP Publishing
Date: 12-02-2004
Publisher: EDP Sciences
Date: 04-03-2005
Publisher: Elsevier BV
Date: 06-2006
Publisher: American Physical Society (APS)
Date: 04-12-2008
Publisher: American Physical Society (APS)
Date: 22-04-2014
Publisher: World Scientific Pub Co Pte Lt
Date: 09-2011
DOI: 10.1142/S0218271811020196
Abstract: High optical power is necessary to increase the sensitivity of advanced gravitational wave detectors. However, it will also induce instabilities. In this paper we review the effects caused by high optical power and potential methods to control those instabilities. Some recent experimental results are presented.
Publisher: American Astronomical Society
Date: 10-2020
Abstract: We present a search for continuous gravitational waves from five radio pulsars, comprising three recycled pulsars (PSR J0437−4715, PSR J0711−6830, and PSR J0737−3039A) and two young pulsars: the Crab pulsar (J0534+2200) and the Vela pulsar (J0835−4510). We use data from the third observing run of Advanced LIGO and Virgo combined with data from their first and second observing runs. For the first time, we are able to match (for PSR J0437−4715) or surpass (for PSR J0711−6830) the indirect limits on gravitational-wave emission from recycled pulsars inferred from their observed spin-downs, and constrain their equatorial ellipticities to be less than 10 −8 . For each of the five pulsars, we perform targeted searches that assume a tight coupling between the gravitational-wave and electromagnetic signal phase evolution. We also present constraints on PSR J0711−6830, the Crab pulsar, and the Vela pulsar from a search that relaxes this assumption, allowing the gravitational-wave signal to vary from the electromagnetic expectation within a narrow band of frequencies and frequency derivatives.
Publisher: Elsevier BV
Date: 10-2013
Publisher: IOP Publishing
Date: 12-04-2017
Publisher: Springer Science and Business Media LLC
Date: 12-2015
Publisher: AIP Publishing
Date: 03-07-2013
DOI: 10.1063/1.4812731
Abstract: Milligram-scale resonators have been shown to be suitable for the creation of 3-mode optoacoustic parametric lifiers, based on a phenomena first predicted for advanced gravitational-wave detectors. To achieve practical optoacoustic parametric devices, high quality factor resonators are required. We present millimetre-scale silicon resonators designed to exhibit a torsional vibration mode with a frequency in the 105–106 Hz range, for observation of 3-mode optoacoustic interactions in a compact table-top system. Our design incorporates an isolation stage and minimizes the acoustic loss from optical coating. We observe a quality factor of 7.5 × 105 for a mode frequency of 401.5 kHz, at room temperature and pressure of 10–3 Pa. We confirmed the mode shape by mapping the litude response across the resonator and comparing to finite element modelling. This study contributes to the development of 3-mode optoacoustic parametric lifiers for use in novel high-sensitivity signal transducers and quantum measurement experiments.
Publisher: IOP Publishing
Date: 16-01-2020
Abstract: GW170817 is the very first observation of gravitational waves originating from the coalescence of two compact objects in the mass range of neutron stars, accompanied by electromagnetic counterparts, and offers an opportunity to directly probe the internal structure of neutron stars. We perform Bayesian model selection on a wide range of theoretical predictions for the neutron star equation of state. For the binary neutron star hypothesis, we find that we cannot rule out the majority of theoretical models considered. In addition, the gravitational-wave data alone does not rule out the possibility that one or both objects were low-mass black holes. We discuss the possible outcomes in the case of a binary neutron star merger, finding that all scenarios from prompt collapse to long-lived or even stable remnants are possible. For long-lived remnants, we place an upper limit of 1.9 kHz on the rotation rate. If a black hole was formed any time after merger and the coalescing stars were slowly rotating, then the maximum baryonic mass of non-rotating neutron stars is at most , and three equations of state considered here can be ruled out. We obtain a tighter limit of for the case that the merger results in a hypermassive neutron star.
Publisher: IOP Publishing
Date: 02-03-2006
Publisher: The Optical Society
Date: 05-02-2014
DOI: 10.1364/AO.53.000841
Publisher: Cambridge University Press (CUP)
Date: 2003
DOI: 10.1071/AS03036
Abstract: An enormous effort is underway worldwide to attempt to detect gravitational waves. If successful, this will open a new frontier in astronomy. An essential portion of this effort is being carried out in Australia by the Australian Consortium for Interferometric Gravitational Astronomy (ACIGA), with research teams working at the Australia National University, University of Western Australia, and University of Adelaide involving scientists and students representing many more institutions and nations. ACIGA is developing ultrastable high-power continuous-wave lasers for the next generation interferometric gravity wave detectors researching the problems associated with high optical power in resonant cavities opening frontiers in advanced interferometry configurations, quantum optics, and signal extraction and is the world's leader in high-performance vibration isolation and suspension design. ACIGA has also been active in theoretical research and modelling of potential astronomical gravitational wave sources, and in developing data analysis detection algorithms. ACIGA has opened a research facility north of Perth, Western Australia, which will be the culmination of these efforts. This paper briefly reviews ACIGA's research activities and the prospects for gravitational wave astronomy in the southern hemisphere.
Publisher: American Astronomical Society
Date: 20-04-2007
DOI: 10.1086/511329
Publisher: American Astronomical Society
Date: 04-09-2019
Publisher: Springer Science and Business Media LLC
Date: 15-05-2017
DOI: 10.1038/NPHYS4118
Publisher: IOP Publishing
Date: 29-06-2017
Publisher: Cambridge University Press
Date: 16-02-2012
Abstract: After decades of research, physicists now know how to detect Einstein's gravitational waves. Advanced gravitational wave detectors, the most sensitive instruments ever created, will be almost certain of detecting the births of black holes throughout the Universe. This book describes the physics of gravitational waves and their detectors. The book begins by introducing the physics of gravitational wave detection and the likely sources of detectable waves. Case studies on the first generation of large scale gravitational wave detectors introduce the technology and set the scene for a review of the experimental issues in creating advanced detectors in which the instrument's sensitivity is limited by Heisenberg's uncertainty principle. The book covers lasers, thermal noise, vibration isolation, interferometer control and stabilisation against opto-acoustic instabilities. This is a valuable reference for graduate students and researchers in physics and astrophysics entering this field.
Publisher: IOP Publishing
Date: 03-07-2014
Publisher: IOP Publishing
Date: 15-03-2004
Publisher: World Scientific Pub Co Pte Lt
Date: 09-2011
DOI: 10.1142/S0218271811020226
Abstract: The AIGO project is the proposed southern hemisphere advanced large scale gravitational wave detector. With this southern hemisphere detector, the global array of ground based gravitational wave detectors will be substantially improved. Here we summarize the current plans for the AIGO detector.
Publisher: IOP Publishing
Date: 12-02-2004
Publisher: AIP Publishing
Date: 22-07-2005
DOI: 10.1063/1.1994988
Abstract: To prevent electrical wiring from mechanically short circuiting in the high performance vibration isolators for gravitational wave detection, we designed a telemetry system. The system provides wireless signal transmission and radiation power supplies. A consideration of heat dissipation of in-vacuum electronic components is presented. The preliminary experiments demonstrated that the telemetry system is feasible.
Publisher: IOP Publishing
Date: 13-02-2004
Publisher: World Scientific Pub Co Pte Lt
Date: 09-2011
DOI: 10.1142/S0218271811020184
Abstract: We report on a seismic isolator with a relatively compact 3 m stack, combining new passive isolation techniques. It consists of three cascaded passive 3D isolator stages suspended from an Ultra Low Frequency (ULF) horizontal Robert linkage stage which itself is suspended from a ULF 3D pre-isolator. The 3D isolators use self-d ing pendulums and Euler springs for the horizontal and vertical stages respectively, while the 3D pre-isolator is the combination of an inverse pendulum which provides low frequency horizontal pre-isolation, and a LaCoste linkage for low frequency vertical pre-isolation. Two isolators suspending mirror test masses have been built to form a 72 m optical cavity in order to test their performance. We report results which demonstrate residual motion at nanometer level at frequencies above 1 Hz.
Publisher: American Physical Society (APS)
Date: 04-09-2019
Publisher: IOP Publishing
Date: 09-06-2009
Publisher: SAGE Publications
Date: 18-06-0015
Abstract: Pain can elevate stress in people with dementia. Although salivary cortisol is used as a biomarker of stress in people with dementia, few studies have reported the feasibility of collection methods to assess salivary cortisol in nursing home residents with both dementia and chronic pain. To explore the feasibility of collecting cortisol via salivary swab as an indicator of stress in people with dementia and chronic pain. Participants ( N = 43) aged ≥ 65 years and living with dementia and chronic pain were randomly assigned to the PARO (in idual, nonfacilitated, 30-min sessions with the robotic seal PARO, 5 days per week for 6 weeks) or usual-care group using computer-generated random numbers. Salivary cortisol was collected in the early morning before the intervention (Week 0) and at the completion of the intervention (Week 6) for comparison. There were multiple challenges associated with saliva collection and analysis, including cognitive impairment of participants, ability to obtain repeated s les with saliva volume adequate for assay, and overall cost. Ultimately, adequate saliva was collected from only 8 participants (both pre- and post-intervention) for assay and quantitative analysis. Considering the multiple challenges involved in obtaining valid saliva s les in this population, salivary cortisol may not be a feasible biomarker of physiological stress in people with dementia and chronic pain.
Publisher: AIP Publishing
Date: 28-10-2003
DOI: 10.1063/1.1614411
Abstract: The seismic signature of a vehicle traveling on the site of the Australian International Gravitational Observatory has been studied using a two-axis seismometer. The main laboratory strongly attenuated the vehicle-induced seismic noise across all frequencies. We find that the magnitude of the vehicle-induced seismic signal followed a d−γ power law, with d the source–detector distance and γ≈1.7±0.4. The results are indicative of strong attenuation of seismic disturbances and are consistent with other measurements of low- litude Rayleigh wave attenuation in similar sandy soil types, a highly desirable property for the site of a gravitational wave observatory. This analysis provides a tool for estimating the magnitude of vehicle-induced seismic noise at the laboratory buildings from more distant sources on and around the site.
Publisher: SPIE
Date: 05-03-2021
DOI: 10.1117/12.2579001
Publisher: American Physical Society (APS)
Date: 17-11-2015
Publisher: IOP Publishing
Date: 12-05-2004
Publisher: IOP Publishing
Date: 29-05-2020
Publisher: IOP Publishing
Date: 02-03-2006
Publisher: AIP
Date: 2005
DOI: 10.1063/1.2032734
Publisher: American Physical Society (APS)
Date: 29-12-2014
Publisher: American Physical Society (APS)
Date: 23-12-2021
Publisher: IOP Publishing
Date: 17-10-2016
Publisher: American Physical Society (APS)
Date: 04-12-2019
Publisher: American Physical Society (APS)
Date: 17-06-2009
Publisher: American Physical Society (APS)
Date: 20-11-2019
Publisher: American Astronomical Society
Date: 26-06-2019
Publisher: IOP Publishing
Date: 07-2008
Publisher: Optica Publishing Group
Date: 12-05-2020
DOI: 10.1364/JOSAB.388766
Abstract: The sensitivity of gravitational wave detectors at high frequencies is currently limited by quantum shot noise. It has been shown theoretically that white light signal recycling using optomechanical negative dispersion filter cavities can increase the gain-bandwidth product of gravitational wave detectors that is usually limited by conventional signal recycling. This sensitivity enhancement is most pronounced at high frequencies above 500 Hz. This technology could be implemented in current facilities or future detectors, but requires thermal noise dilution of the mechanical resonator. Here we provide a theoretical analysis of a double end-mirror sloshing (DEMS) cavity to achieve strong thermal noise dilution with low radiation pressure noise and suppression of optical anti-d ing. We demonstrate experimentally that the DEMS cavity can be tuned to a regime that is expected to support these favorable conditions.
Publisher: American Physical Society (APS)
Date: 12-06-2006
Publisher: AIP Publishing
Date: 10-2008
DOI: 10.1063/1.2982239
Abstract: This paper reports automatic compensation of strong thermal lensing in a suspended 80 m optical cavity with sapphire test mass mirrors. Variation of the transmitted beam spot size is used to obtain an error signal to control the heating power applied to the cylindrical surface of an intracavity compensation plate. The negative thermal lens created in the compensation plate compensates the positive thermal lens in the sapphire test mass, which was caused by the absorption of the high intracavity optical power. The results show that feedback control is feasible to compensate the strong thermal lensing expected to occur in advanced laser interferometric gravitational wave detectors. Compensation allows the cavity resonance to be maintained at the fundamental mode, but the long thermal time constant for thermal lensing control in fused silica could cause difficulties with the control of parametric instabilities.
Publisher: American Astronomical Society
Date: 20-04-2020
Publisher: IOP Publishing
Date: 11-02-2004
Publisher: Optica Publishing Group
Date: 2020
DOI: 10.1364/CLEOPR.2020.C1A_3
Abstract: We report 2-μm single-frequency polarization-maintaining fiber-laser with optimized frequency noise below 100 Hz/Hz1/2 between 30 Hz to 100 kHz in which a single-frequency 1.5μm DFB diode and Er-doped fiber- lifier is used as pumping source.
Publisher: IOP Publishing
Date: 11-02-2004
Publisher: IOP Publishing
Date: 20-02-2006
Publisher: American Astronomical Society
Date: 26-08-2020
Publisher: American Astronomical Society
Date: 13-12-2017
Publisher: IOP Publishing
Date: 05-2010
Publisher: American Physical Society (APS)
Date: 18-10-2019
Publisher: IOP Publishing
Date: 03-12-2014
Publisher: American Physical Society (APS)
Date: 08-10-2024
Publisher: IOP Publishing
Date: 06-04-2010
Publisher: AIP Publishing
Date: 26-06-2023
DOI: 10.1063/5.0137001
Abstract: We experimentally demonstrate that the optical spring effect can be modified using an optical parametric lifier in an opto-mechanical cavity. The theoretical analysis shows that both the gain and phase of the optical parametric lifier can modify the frequency of a mechanical resonator in an opto-mechanical cavity. This modification could be used to tune the frequency of peak sensitivity of gravitational wave detectors. The experimental results show a factor of 1.2 ± 0.8 increase in mechanical resonator frequency shift induced by optical spring by tuning the optical parametric lifier gain.
Publisher: American Astronomical Society
Date: 18-12-2017
Publisher: Springer Science and Business Media LLC
Date: 11-09-2011
DOI: 10.1038/NPHYS2083
Publisher: Springer Science and Business Media LLC
Date: 16-10-2017
DOI: 10.1038/NATURE24471
Abstract: On 17 August 2017, the Advanced LIGO and Virgo detectors observed the gravitational-wave event GW170817-a strong signal from the merger of a binary neutron-star system. Less than two seconds after the merger, a γ-ray burst (GRB 170817A) was detected within a region of the sky consistent with the LIGO-Virgo-derived location of the gravitational-wave source. This sky region was subsequently observed by optical astronomy facilities, resulting in the identification of an optical transient signal within about ten arcseconds of the galaxy NGC 4993. This detection of GW170817 in both gravitational waves and electromagnetic waves represents the first 'multi-messenger' astronomical observation. Such observations enable GW170817 to be used as a 'standard siren' (meaning that the absolute distance to the source can be determined directly from the gravitational-wave measurements) to measure the Hubble constant. This quantity represents the local expansion rate of the Universe, sets the overall scale of the Universe and is of fundamental importance to cosmology. Here we report a measurement of the Hubble constant that combines the distance to the source inferred purely from the gravitational-wave signal with the recession velocity inferred from measurements of the redshift using the electromagnetic data. In contrast to previous measurements, ours does not require the use of a cosmic 'distance ladder': the gravitational-wave analysis can be used to estimate the luminosity distance out to cosmological scales directly, without the use of intermediate astronomical distance measurements. We determine the Hubble constant to be about 70 kilometres per second per megaparsec. This value is consistent with existing measurements, while being completely independent of them. Additional standard siren measurements from future gravitational-wave sources will enable the Hubble constant to be constrained to high precision.
Publisher: Springer Science and Business Media LLC
Date: 12-2015
Publisher: IOP Publishing
Date: 12-02-2004
Publisher: IOP Publishing
Date: 11-02-2004
Publisher: Springer Science and Business Media LLC
Date: 09-2005
Publisher: AIP Publishing
Date: 07-2018
DOI: 10.1063/1.5021503
Abstract: Low acoustic loss suspension systems are essential components in low thermal noise instruments including gravitational wave detectors. Monolithic fused silica suspensions have been used successfully with fused silica test masses but may not be suitable in next generation detectors that may use sapphire or silicon test masses. Here we report a study of a modular suspension system with high replaceability. The system is based on high pressure gravitationally attached mechanical contacts which have been previously shown to contribute low acoustic losses to sapphire resonators. Here we combine high pressure contacts with cantilevers and fibres to create sets of four suspension modules which are shown to have low loss contributions to fused silica test masses in a 74-m high-finesse optical cavity. Results are combined with finite element simulations to estimate the strain energy distributions of the eigenmodes. By combining the simulations and measurement results, the test mass loss angle due to the coupling to the suspension system was estimated. The modular suspension system is shown to contribute & % to the total test mass acoustic loss. Such suspension systems could have applications for test masses or subsystems in next generation gravitational wave detectors.
Publisher: Optica Publishing Group
Date: 04-05-2021
DOI: 10.1364/OE.425433
Abstract: We present a novel design for an angle sensor based on photon coupling to internal optical modes of a two dimensional photonic crystal. We show in simulation that an implementation of this design could achieve sensitivities as high as 1.61 × 10 6 V/rad, which in principle allows for angle measurements with a noise floor of 2.98 × 10 −14 rad / Hz at the photodiode noise equivalent power. We discuss the limitations of this design and predict the impact these limitations have on the sensitivity as well as the possible ways to further increase the devices sensitivity. As a proof of concept, we demonstrate experimentally a photonic crystal with an angle sensitive mode.
Publisher: IOP Publishing
Date: 29-07-2020
Publisher: American Physical Society (APS)
Date: 25-06-2018
Publisher: American Astronomical Society
Date: 16-10-2017
Publisher: Elsevier BV
Date: 07-2006
Publisher: Elsevier BV
Date: 11-2013
Publisher: Elsevier BV
Date: 2021
Publisher: The Optical Society
Date: 11-05-2015
DOI: 10.1364/OL.40.002337
Publisher: IOP Publishing
Date: 26-08-2014
Publisher: Optica Publishing Group
Date: 19-01-2021
DOI: 10.1364/OE.415298
Abstract: We investigated the frequency noise coupling mechanism of a 2 μ m polarization-maintaining single frequency fiber laser (SFFL) theoretically and experimentally. The coupling of pump’s relative intensity noise (RIN) to frequency noise of a single-frequency high-gain silica fiber laser is shown experimentally to be consistent with a theoretical model where thermal expansion and thermo-optic effect mediate the coupling. The measured and theoretical frequency noise of the 2 μ m SFFL with three pump sources is compared. We find using a 1550 nm single frequency laser pump source produces the lowest frequency noise, less than 100 H z / H z at frequencies higher than 100 Hz.
Publisher: World Scientific Pub Co Pte Lt
Date: 20-10-2015
DOI: 10.1142/S0217751X15450190
Abstract: This paper begins by reviewing the development of gravitational wave astronomy from the first predictions of gravitational waves to development of technologies across the entire gravitational wave spectrum, and then focuses on the current status of ground based gravitational wave detectors. With substantial improvements already demonstrated in early commissioning it is emphasised that Advanced detectors are on track for first detection of gravitational waves. The importance of a worldwide array of detectors is emphasised, and recent results are shown that demonstrate the continued advantage of a southern hemisphere detector. Finally it is shown that a north–south pair of 8 km arm length detectors would give rise to a dramatic improvement in event rate, enabling a pair of detectors to encompass a 64-times larger volume of the universe, to conduct a census on all stellar mass black hole mergers to [Formula: see text] and to observe neutron star mergers to a distance of [Formula: see text][Formula: see text]800 Mpc.
Publisher: AIP Publishing
Date: 10-2022
DOI: 10.1063/5.0106565
Abstract: Thermal noise in test mass substrates and coatings is a significant noise contribution in the detection band of current and proposed future gravitational wave detectors. Substrate thermal noise can be reduced by using high mechanical Q-factor materials and cooling the test mass mirrors. Silicon is a promising potential candidate for the next generation detector test masses. The low thermal expansion and high thermal conductivity of silicon allow efficient cryogenic operation, and a significant increase in the amount of optical power that can be used in the detectors by decreasing thermal deformation and aberration. Mechanical stress, damage, poor surface quality or contamination can result in increased loss and thermal noise. Therefore, the characterization of mechanical loss in silicon test masses is necessary. In this project, we developed a technique to measure high Q-factor mechanical modes. We used finite element modeling to optimize the design of the test mass support structure to minimize the loss coupling from the support structure over a wide frequency range. Mechanical Q-factors of the order of 107 were achieved for several modes of a 10 cm diam. × 3 cm cylindrical silicon test mass with such a support at room temperature.
Publisher: AIP Publishing
Date: 11-2009
DOI: 10.1063/1.3250861
Abstract: High performance vibration isolators are required for ground based gravitational wave detectors. To attain very high performance at low frequencies we have developed multistage isolators for the proposed Australian International Gravitational Observatory detector in Australia. New concepts in vibration isolation including self-d ing, Euler springs, LaCoste springs, Roberts linkages, and double preisolation require novel sensors and actuators. Double preisolation enables internal feedback to be used to suppress low frequency seismic noise. Multidegree of freedom control systems are required to attain high performance. Here we describe the control components and control systems used to control all degrees of freedom. Feedback forces are injected at the preisolation stages and at the penultimate suspension stage. There is no direct actuation on test masses. A digital local control system hosted on a digital signal processor maintains alignment and position, corrects drifts, and d s the low frequency linear and torsional modes without exciting the very high Q-factor test mass suspension. The control system maintains an optical cavity locked to a laser with a high duty cycle even in the absence of an autoalignment system. An accompanying paper presents the mechanics of the system, and the optical cavity used to determine isolation performance. A feedback method is presented, which is expected to improve the residual motion at 1 Hz by more than one order of magnitude.
Publisher: SPIE
Date: 11-02-2010
DOI: 10.1117/12.847173
Publisher: Oxford University Press (OUP)
Date: 29-11-2017
Publisher: Optica Publishing Group
Date: 20-04-2006
DOI: 10.1364/AO.45.002631
Abstract: While the thermomechanical properties of sapphire make it an excellent candidate of test mass for advanced laser interferometers, its optical quality is not well understood or well controlled. We have studied the results from high-resolution measurements of scattering, absorption, and birefringence in test-mass s les to better understand issues of quality. S les show large-scale scattering structures clearly linked to the crystal-growth process. S les characterized by the presence of point defects have significantly lower scattering (except at the point defects). In general on a large scale, high scattering also correlates with higher absorption and higher average birefringence inhomogeneity. However, on a smaller scale there is not a clear point-to-point correlation between scattering and absorption. Often a large-scale scattering structure is spatially displaced by tens of millimeters from a similar absorption structure, indicating that quite separate microscopic mechanisms give rise to scattering and absorption. The spatial displacements indicate that absorption centers and scattering centers are laid down during crystal growth at different distances from the solid-liquid interface. We suggest that absorption may be linked to F centers, while scattering may be linked to impurities such as iron.
Publisher: AIP Publishing
Date: 03-2005
DOI: 10.1063/1.1867472
Abstract: We demonstrate a scheme for radiation pressure force actuation for noncontacting control of a suspended test mass. We present results of the frequency response and active d ing of a 35 g low frequency resonator under radiation pressure using less than 1 W of diode laser power.
Publisher: AIP Publishing
Date: 12-2018
DOI: 10.1063/1.5049508
Abstract: Advanced gravitational wave detectors use suspended test masses to form optical resonant cavities for enhancing the detector sensitivity. These cavities store hundreds of kilowatts of coherent light and even higher optical power for future detectors. With such high optical power, the radiation pressure effect inside the cavity creates a sufficiently strong coupling between test masses whose dynamics are significantly altered. The dynamics of two independent nearly free masses become a coupled mechanical resonator system. The transfer function of the local control system used for controlling the test masses is modified by the radiation pressure effect. The changes in the transfer function of the local control systems can result in a new type of angular instability which occurs at only 1.3% of the Sidles-Sigg instability threshold power. We report the experimental results on a 74 m suspended cavity with a few kilowatts of circulating power, for which the power to mass ratio is comparable to the current Advanced LIGO. The radiation pressure effect on the test masses behaves like an additional optical feedback with respect to the local angular control, potentially making the mirror control system unstable. When the local angular control system is optimised for maximum stability margin, the instability threshold power increases from 4 kW to 29 kW. The system behaviour is consistent with our simulation, and the power dependent evolution of both the cavity soft and hard mode is observed. We show that this phenomenon is likely to significantly affect the proposed gravitational wave detectors that require very high optical power.
Publisher: AIP Publishing
Date: 22-12-2004
DOI: 10.1063/1.1823651
Abstract: This article describes an automatic Rayleigh scattering mapping system (ARSMS), which enables quantitative high-resolution three-dimensional mapping of inhomogeneities in optical materials. The ARSMS allows large high-grade test mass s les for gravitational wave detectors to be evaluated to ensure that an adequate low level of scattering is achieved. The ARSMS combines proprietary camera software with data analysis software and control software to achieve fully automatic operation with graphical user interfaces. This article presents the instrument concept and ex les of the output. Device mapping in all degrees of freedom is shown to be better than 0.5mm, with scattering sensitivity better than 0.5ppm∕cm. This system is able to scan and map the Rayleigh scattering of large s les in both of cylindrical and rectangular s les using cylindrical and Cartesian coordinates.
Publisher: Springer Science and Business Media LLC
Date: 09-2005
Publisher: IOP Publishing
Date: 06-2012
Publisher: AIP
Date: 2010
DOI: 10.1063/1.3460208
Publisher: IOP Publishing
Date: 02-03-2006
Publisher: Cambridge University Press
Date: 16-02-2012
Publisher: American Physical Society (APS)
Date: 26-03-2015
Publisher: Cambridge University Press
Date: 16-02-2012
Publisher: Cambridge University Press
Date: 16-02-2012
Publisher: American Physical Society (APS)
Date: 05-05-2015
Publisher: American Physical Society (APS)
Date: 03-04-2023
Publisher: IOP Publishing
Date: 05-06-2017
Publisher: Optica Publishing Group
Date: 02-02-2009
DOI: 10.1364/OE.17.002149
Abstract: Marginally stable power recycling cavities are being used by nearly all interferometric gravitational wave detectors.With stability factors very close to unity the frequency separation of the higher order optical modes is smaller than the cavity bandwidth. As a consequence these higher order modes will resonate inside the cavity distorting the spatial mode of the interferometer control sidebands. Without losing generality we study and compare two designs of stable power recycling cavities for the proposed 5 kilometer long Australian International Gravitational Observatory (AIGO), a high power advanced interferometric gravitational wave detector. The length of various optical cavities that form the interferometer and the modulation frequencies that generate the control sidebands are also selected.
Publisher: IOP Publishing
Date: 10-08-2000
Publisher: IOP Publishing
Date: 06-04-2010
Publisher: American Physical Society (APS)
Date: 02-04-2020
Publisher: American Physical Society (APS)
Date: 04-2005
Publisher: IOP Publishing
Date: 24-10-2007
Publisher: Optica Publishing Group
Date: 17-05-2007
Publisher: American Physical Society (APS)
Date: 02-09-2020
Publisher: American Physical Society (APS)
Date: 16-12-2011
Publisher: Springer Science and Business Media LLC
Date: 15-02-2021
DOI: 10.1038/S42005-021-00526-2
Abstract: Gravitational waves from the neutron star coalescence GW170817 were observed from the inspiral, but not the high frequency postmerger nuclear matter motion. Optomechanical white light signal recycling has been proposed for achieving broadband sensitivity in gravitational wave detectors, but has been reliant on development of suitable ultra-low loss mechanical components. Here we show demonstrated optomechanical resonators that meet loss requirements for a white light signal recycling interferometer with strain sensitivity below 10 −24 Hz −1/2 at a few kHz. Experimental data for two resonators are combined with analytic models of interferometers similar to LIGO to demonstrate enhancement across a broader band of frequencies versus dual-recycled Fabry-Perot Michelson detectors. Candidate resonators are a silicon nitride membrane acoustically isolated by a phononic crystal, and a single-crystal quartz acoustic cavity. Optical power requirements favour the membrane resonator, while thermal noise performance favours the quartz resonator. Both could be implemented as add-on components to existing detectors.
Publisher: Optica Publishing Group
Date: 31-08-2020
DOI: 10.1364/OL.402617
Abstract: We demonstrated an ultra-low-noise polarization-maintaining (PM) single-frequency fiber laser at 2 µm. Both relative intensity noise (RIN) and frequency noise were improved by suppressing the pump source RIN using feedback control. After a two-stage T m 3 + -doped PM fiber lifier, the output power reached about 5 W, and the lifier did not introduce any observable extra frequency noise. The frequency noise was less than 100 H z / H z above 13 Hz, which is comparable to the frequency noise of a typical seed laser of the Advanced LIGO high-power laser. The central wavelength was measured to be 1990.25 nm, with a polarization extinction ratio above 24 dB.
Publisher: SPIE
Date: 29-09-2004
DOI: 10.1117/12.581300
Publisher: Cambridge University Press
Date: 16-02-2012
Publisher: Elsevier BV
Date: 08-2018
Publisher: American Physical Society (APS)
Date: 06-08-2008
Publisher: IOP Publishing
Date: 02-03-2006
Publisher: Springer Science and Business Media LLC
Date: 10-2003
Publisher: IOP Publishing
Date: 24-03-2006
Publisher: American Physical Society (APS)
Date: 11-07-2019
Publisher: Oxford University Press (OUP)
Date: 11-08-2017
DOI: 10.1093/NSR/NWX089
Publisher: American Physical Society (APS)
Date: 10-10-2014
Publisher: American Physical Society (APS)
Date: 06-2009
Publisher: IOP Publishing
Date: 05-03-2020
Publisher: IOP Publishing
Date: 10-02-2017
Publisher: AIP Publishing
Date: 04-2019
DOI: 10.1063/1.5088733
Abstract: We present an optical walk-off sensor with an angular sensitivity of a few nrad/Hz above 1 mHz and 0.4 nrad/Hz above 100 mHz. This experiment furthers previous research into the walk-off sensor capabilities through an improved input laser, reduction in air optical travel length, and position control on photo-diodes. The angle change measured in this walk-off scheme features a knife edge to split the beam into two separate fiber coupled photo-diodes to minimize power dissipation in the thermally sensitive region. Using this photo-diode power differential as an error signal, a simple control scheme is used to maintain the balance position, increasing common mode rejection and improving dynamic range by mitigating thermal drift. The in-vacuum component of the optical readout takes up a volume less than 100 mm × 100 mm × 50 mm. This experiment shows that the walk-off sensor provides a simple and compact readout scheme with nanoradian sensitivity for angle sensing at low frequencies.
Start Date: 2012
End Date: 2014
Funder: Australian Research Council
View Funded ActivityStart Date: 2007
End Date: 2011
Funder: Australian Research Council
View Funded ActivityStart Date: 2011
End Date: 2011
Funder: Australian Research Council
View Funded ActivityStart Date: 2016
End Date: 2018
Funder: Australian Research Council
View Funded ActivityStart Date: 2021
End Date: 2024
Funder: Australian Research Council
View Funded ActivityStart Date: 2008
End Date: 2008
Funder: Australian Research Council
View Funded ActivityStart Date: 2020
End Date: 2020
Funder: Australian Research Council
View Funded ActivityStart Date: 2012
End Date: 2014
Funder: Australian Research Council
View Funded ActivityStart Date: 2016
End Date: 2016
Funder: Australian Research Council
View Funded ActivityStart Date: 2017
End Date: 2021
Funder: Australian Research Council
View Funded ActivityStart Date: 2017
End Date: 2023
Funder: Australian Research Council
View Funded ActivityStart Date: 2016
End Date: 12-2016
Amount: $595,400.00
Funder: Australian Research Council
View Funded ActivityStart Date: 05-2017
End Date: 12-2023
Amount: $1,097,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 05-2012
End Date: 12-2016
Amount: $330,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2008
End Date: 03-2010
Amount: $600,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 06-2020
End Date: 06-2021
Amount: $700,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 09-2021
End Date: 08-2025
Amount: $3,000,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 07-2016
End Date: 12-2017
Amount: $650,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 05-2011
End Date: 12-2012
Amount: $550,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 02-2007
End Date: 01-2012
Amount: $907,535.00
Funder: Australian Research Council
View Funded ActivityStart Date: 04-2017
End Date: 03-2024
Amount: $31,300,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2012
End Date: 12-2015
Amount: $370,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 07-2022
End Date: 06-2023
Amount: $385,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 04-2024
End Date: 03-2031
Amount: $35,000,000.00
Funder: Australian Research Council
View Funded Activity