1
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Bode N, Holmes Z, Ng S, vonBehren B, Ottaway D, Willke B. Multiple beam coherent combination via an optical ring resonator. Opt Lett 2023; 48:4717-4720. [PMID: 37656594 DOI: 10.1364/ol.500684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 08/14/2023] [Indexed: 09/03/2023]
Abstract
Future gravitational wave detectors (GWDs) require low noise, single frequency, continuous wave lasers with excellent beam quality and powers in excess of 500 W. Low noise laser amplifiers with high spatial purity have been demonstrated up to 300 W. For higher powers, coherent beam combination can overcome scaling limitations. In this Letter we introduce a new, to the best of our knowledge, combination scheme that uses a bow-tie resonator to combine three laser beams with simultaneous spatial filtering performance.
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2
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Schiworski M, Bossilkov V, Blair C, Brown D, Jones A, Ottaway D, Zhao C. Observing the optical modes of parametric instability. Opt Lett 2022; 47:1685-1688. [PMID: 35363709 DOI: 10.1364/ol.454102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 03/01/2022] [Indexed: 06/14/2023]
Abstract
Parametric instability (PI) is a phenomenon that results from resonant interactions between optical and acoustic modes of a laser cavity. This is problematic in gravitational wave interferometers where the high intracavity power and low mechanical loss mirror suspension systems create an environment where three-mode PI will occur without intervention. We demonstrate a technique for real-time imaging of the amplitude and phase of the optical modes of PI yielding, to the best of the authors' knowledge, the first ever images of this phenomenon which could form part of active control strategies for future detectors.
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3
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Smith R, Borhanian S, Sathyaprakash B, Hernandez Vivanco F, Field SE, Lasky P, Mandel I, Morisaki S, Ottaway D, Slagmolen BJJ, Thrane E, Töyrä D, Vitale S. Bayesian Inference for Gravitational Waves from Binary Neutron Star Mergers in Third Generation Observatories. Phys Rev Lett 2021; 127:081102. [PMID: 34477440 DOI: 10.1103/physrevlett.127.081102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 06/20/2021] [Accepted: 07/09/2021] [Indexed: 06/13/2023]
Abstract
Third generation (3G) gravitational-wave detectors will observe thousands of coalescing neutron star binaries with unprecedented fidelity. Extracting the highest precision science from these signals is expected to be challenging owing to both high signal-to-noise ratios and long-duration signals. We demonstrate that current Bayesian inference paradigms can be extended to the analysis of binary neutron star signals without breaking the computational bank. We construct reduced-order models for ∼90-min-long gravitational-wave signals covering the observing band (5-2048 Hz), speeding up inference by a factor of ∼1.3×10^{4} compared to the calculation times without reduced-order models. The reduced-order models incorporate key physics including the effects of tidal deformability, amplitude modulation due to Earth's rotation, and spin-induced orbital precession. We show how reduced-order modeling can accelerate inference on data containing multiple overlapping gravitational-wave signals, and determine the speedup as a function of the number of overlapping signals. Thus, we conclude that Bayesian inference is computationally tractable for the long-lived, overlapping, high signal-to-noise-ratio events present in 3G observatories.
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Affiliation(s)
- Rory Smith
- School of Physics and Astronomy, Monash University, Victoria 3800, Australia
- OzGrav: The ARC Centre of Excellence for Gravitational Wave Discovery, Clayton, Victoria 3800, Australia
| | - Ssohrab Borhanian
- Institute for Gravitation and the Cosmos, Department of Physics, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Bangalore Sathyaprakash
- Institute for Gravitation and the Cosmos, Department of Physics, Pennsylvania State University, University Park, Pennsylvania 16802, USA
- Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, Pennsylvania 16802, USA
- School of Physics and Astronomy, Cardiff University, Cardiff CF24 3AA, United Kingdom
| | - Francisco Hernandez Vivanco
- School of Physics and Astronomy, Monash University, Victoria 3800, Australia
- OzGrav: The ARC Centre of Excellence for Gravitational Wave Discovery, Clayton, Victoria 3800, Australia
| | - Scott E Field
- Department of Mathematics and Center for Scientific Computing and Visualization Research, University of Massachusetts, Dartmouth, Massachusetts 02747, USA
| | - Paul Lasky
- School of Physics and Astronomy, Monash University, Victoria 3800, Australia
- OzGrav: The ARC Centre of Excellence for Gravitational Wave Discovery, Clayton, Victoria 3800, Australia
| | - Ilya Mandel
- School of Physics and Astronomy, Monash University, Victoria 3800, Australia
- OzGrav: The ARC Centre of Excellence for Gravitational Wave Discovery, Clayton, Victoria 3800, Australia
| | - Soichiro Morisaki
- Department of Physics, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201, USA
| | - David Ottaway
- OzGrav, University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Bram J J Slagmolen
- OzGrav, ANU Centre for Gravitational Astrophysics, Research Schools of Physics, and Astronomy and Astrophysics, The Australian National University, Australian Capital Territory 2601, Australia
| | - Eric Thrane
- School of Physics and Astronomy, Monash University, Victoria 3800, Australia
- OzGrav: The ARC Centre of Excellence for Gravitational Wave Discovery, Clayton, Victoria 3800, Australia
| | - Daniel Töyrä
- OzGrav, ANU Centre for Gravitational Astrophysics, Research Schools of Physics, and Astronomy and Astrophysics, The Australian National University, Australian Capital Territory 2601, Australia
| | - Salvatore Vitale
- LIGO Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
- Department of Physics and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
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4
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Brown D, Cao HT, Ciobanu A, Veitch P, Ottaway D. Differential wavefront sensing and control using radio-frequency optical demodulation. Opt Express 2021; 29:15995-16006. [PMID: 34154172 DOI: 10.1364/oe.425590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 04/29/2021] [Indexed: 06/13/2023]
Abstract
Differential wavefront sensing is an essential technique for optimising the performance of many precision interferometric experiments. Perhaps the most extensive application of this is for alignment sensing using radio-frequency beats measured with quadrant photodiodes. Here we present a new technique that uses optical demodulation to measure such optical beats at high resolutions using commercial laboratory equipment. We experimentally demonstrate that the images captured can be digitally processed to generate wavefront error signals and use these in a closed loop control system for correct wavefront errors for alignment and mode-matching a beam into an optical cavity to 99.9%. This experiment paves the way for the correction of even higher order errors when paired with higher order wavefront actuators. Such a sensing scheme could find use in optimizing complex interferometers consisting of coupled cavities, such as those found in gravitational wave detectors, or simply just for sensing higher order wavefront errors in heterodyne interferometric table-top experiments.
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5
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Ram R, Owen ND, Kalnins C, Cook NJ, Ehrig K, Etschmann B, Rollog M, Fu W, Vaughan J, Pring A, Pownceby MI, Spooner N, Shaw R, Howard D, Hooker AM, Ottaway D, Questiaux D, Brugger J. Understanding the mobility and retention of uranium and its daughter products. J Hazard Mater 2021; 410:124553. [PMID: 33223312 DOI: 10.1016/j.jhazmat.2020.124553] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 11/07/2020] [Accepted: 11/10/2020] [Indexed: 06/11/2023]
Abstract
Knowledge of the behavior of technologically enhanced naturally occurring radioactive materials derived through the decay of U and its daughter products, and their subsequent fractionation, mobilization and retention, is essential to develop effective mitigation strategies and long-term radiological risk prediction. In the present study, multiple state-of-the-art, spatially resolved micro-analytical characterization techniques were combined to systematically track the liberation and migration of radionuclides (RN) from U-bearing phases in an Olympic Dam Cu flotation concentrate following sulfuric-acid-leach processing. The results highlighted the progressive dissolution of U-bearing minerals (mainly uraninite) leading to the release, disequilibrium and ultimately upgrade of daughter RN from the parent U. This occurred in conjunction with primary Cu-Fe-sulfide minerals undergoing coupled-dissolution reprecipitation to the porous secondary Cu-mineral, covellite. The budget of RN remaining in the leached concentrate was split between RN still hosted in the original U-bearing minerals, and RN that were mobilized and subsequently sorbed/precipitated onto porous covellite and auxiliary gangue mineral phases (e.g. barite). Further grinding of the flotation concentrate prior to sulfuric-acid-leach led to dissolution of U-bearing minerals previously encapsulated within Cu-Fe-sulfide minerals, resulting in increased release and disequilibrium of daughter RN, and causing further RN upgrade. The various processes that affect RN (mobility, sorption, precipitation) and sulfide minerals (coupled-dissolution reprecipitation and associated porosity generation) occur continuously within the hydrometallurgical circuit, and their interplay controls the rapid and highly localized enrichment of RN. The innovative combination of tools developed here reveal the heterogeneous distribution and fractionation of the RN in the ores following hydrometallurgical treatment at nm to cm-scales in exquisite detail. This approach provides an effective blueprint for understanding of the mobility and retention of U and its daughter products in complex anthropogenic and natural processes in the mining and energy industries.
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Affiliation(s)
- Rahul Ram
- School of Earth, Atmosphere and Environment, 9 Rainforest Walk, Monash University, Clayton, VIC 3168, Australia.
| | - Nicholas D Owen
- School of Earth, Atmosphere and Environment, 9 Rainforest Walk, Monash University, Clayton, VIC 3168, Australia
| | - Chris Kalnins
- Institute for Photonics and Advanced Sensing and School of Physical Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Nigel J Cook
- School of Civil, Environmental and Mining Engineering, The University of Adelaide, SA 5005, Australia
| | - Kathy Ehrig
- BHP Olympic Dam, Adelaide, SA 5000, Australia
| | - Barbara Etschmann
- School of Earth, Atmosphere and Environment, 9 Rainforest Walk, Monash University, Clayton, VIC 3168, Australia
| | - Mark Rollog
- School of Civil, Environmental and Mining Engineering, The University of Adelaide, SA 5005, Australia
| | - Weng Fu
- School of Chemical Engineering, The University of Queensland, Level 3, Chemical Engineering Building (74), St Lucia, QLD 4072, Australia
| | - James Vaughan
- School of Chemical Engineering, The University of Queensland, Level 3, Chemical Engineering Building (74), St Lucia, QLD 4072, Australia
| | - Allan Pring
- College of Science and Engineering, Flinders University, Bedford Park, SA 5042, Australia
| | | | - Nigel Spooner
- Institute for Photonics and Advanced Sensing and School of Physical Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Ruth Shaw
- Institute for Photonics and Advanced Sensing and School of Physical Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Daryl Howard
- Australian Synchrotron, 800 Blackburn Road, Clayton, VIC 3168, Australia
| | - Anthony M Hooker
- Institute for Photonics and Advanced Sensing and School of Physical Sciences, University of Adelaide, Adelaide, SA, Australia
| | - David Ottaway
- Institute for Photonics and Advanced Sensing and School of Physical Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Danielle Questiaux
- Institute for Photonics and Advanced Sensing and School of Physical Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Joël Brugger
- School of Earth, Atmosphere and Environment, 9 Rainforest Walk, Monash University, Clayton, VIC 3168, Australia.
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6
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Kalnins CAG, Ottaway D, Cook NJ, Spooner NA. Quantification of radionuclide distribution and migration during Cu-(Fe)-sulphide mineral processing by alpha particle autoradiography. J Environ Radioact 2021; 228:106514. [PMID: 33360423 DOI: 10.1016/j.jenvrad.2020.106514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 10/05/2020] [Accepted: 12/14/2020] [Indexed: 06/12/2023]
Abstract
Understanding the movement of radionuclides (RNs) between different mineral hosts during processing of base metal ores is critical for accurate modelling of RN deportment and optimisation of processes designed to reduce or eliminate RNs. Here, we demonstrate that spatially resolving quantitative alpha particle autoradiography combined with backscatter electron imaging and energy dispersive X-ray spectroscopy (EDS) can establish the correlation between alpha-emitting RNs (notably 226Ra and 210Po, daughters of the abundant 238U decay series) and certain minerals, in different stages of processing. This is achieved by locating the RNs to a specific mineral grain, the species of which can subsequently be identified using EDS. The mineralogy of RN-associated grains can then be compared with the mineral suite and relative abundances of the species within the sample, by relating how often each mineral is associated with alpha decay-events. In the processing of uranium-bearing copper ores, migration of alpha-emitting RN daughters of the 238U series were observed, and these RNs were demonstrated to correlate strongly with barite, bornite and covellite over other coexisting minerals.
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Affiliation(s)
- Christopher A G Kalnins
- Institute for Photonics & Advanced Sensing (IPAS) and School of Physical Sciences, University of Adelaide, Adelaide, 5005, Australia; Australian Research Council (ARC), Research Hub for Australian Copper-Uranium, Australia.
| | - David Ottaway
- Institute for Photonics & Advanced Sensing (IPAS) and School of Physical Sciences, University of Adelaide, Adelaide, 5005, Australia; Australian Research Council (ARC), Research Hub for Australian Copper-Uranium, Australia
| | - Nigel J Cook
- School of Civil, Environmental and Mining Engineering, The University of Adelaide, Adelaide, SA, 5005, Australia; Australian Research Council (ARC), Research Hub for Australian Copper-Uranium, Australia
| | - Nigel A Spooner
- Institute for Photonics & Advanced Sensing (IPAS) and School of Physical Sciences, University of Adelaide, Adelaide, 5005, Australia; Defence Science and Technology Group, Edinburgh, 5111, Australia; Australian Research Council (ARC), Research Hub for Australian Copper-Uranium, Australia
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7
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Cao HT, Brooks A, Ng SWS, Ottaway D, Perreca A, Richardson JW, Chaderjian A, Veitch PJ. High dynamic range thermally actuated bimorph mirror for gravitational wave detectors. Appl Opt 2020; 59:2784-2790. [PMID: 32225844 DOI: 10.1364/ao.376764] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 02/03/2020] [Indexed: 06/10/2023]
Abstract
Adaptive optics are crucial for overcoming the fabrication limits on mirror curvature in high-precision interferometry. We describe a low-cost thermally actuated bimorph mirror with 200 mD linear response, which meets dynamic range and low aberration requirements for the ${\rm{A}} + $A+ upgrade of the Laser Interferometer Gravitational-wave Observatory (LIGO). Its deformation and operation limits were measured and verified against finite element simulation.
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8
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Whittaker CA, Santos AM, Kalnins CA, Ebendorff-Heidepriem H, Ottaway D, Spooner NA. Evaluating the energy dependence of various polystyrene based plastic scintillators. RADIAT MEAS 2019. [DOI: 10.1016/j.radmeas.2019.01.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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9
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Kalnins CAG, Spooner NA, Clarke MJP, Ottaway D. Alpha particle autoradiography for high spatial resolution mapping of radionuclides. J Environ Radioact 2019; 197:9-15. [PMID: 30476811 DOI: 10.1016/j.jenvrad.2018.11.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 10/15/2018] [Accepted: 11/12/2018] [Indexed: 06/09/2023]
Abstract
An autoradiographic technique capable of determining the spatial location of radioactive isotopes within materials on the scale of micrometers is demonstrated in low-activity mineral samples, where the concentrations of radionuclides with short half lives is small and below the detection limits of current measurement techniques. The location of certain radionuclide species within samples with complex structures on the micron scale can yield valuable information, however current methods do not have the spatial resolution required for this purpose. We demonstrate the use of an autoradiographic emulsion to directly image alpha particle events in samples with low radionuclide concentrations, allowing spatial resolution of radionuclide locations on the order of several microns. Exposure over a long time period allows sufficient integration of decay events enabling analysis of samples with low activity but large area, (less than 1×10-4 Bq/mm2). The use of polarising filters to increase contrast between the alpha particle tracks and the substrate during imaging demonstrates the viability of the technique on samples with a complex structure.
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Affiliation(s)
- Christopher A G Kalnins
- Institute for Photonics & Advanced Sensing and School of Physical Sciences, University of Adelaide, Adelaide, 5005, Australia.
| | - Nigel A Spooner
- Institute for Photonics & Advanced Sensing and School of Physical Sciences, University of Adelaide, Adelaide, 5005, Australia; Defence Science and Technology Group, Edinburgh, 5111, Australia
| | - Michael J P Clarke
- Institute for Photonics & Advanced Sensing and School of Physical Sciences, University of Adelaide, Adelaide, 5005, Australia
| | - David Ottaway
- Institute for Photonics & Advanced Sensing and School of Physical Sciences, University of Adelaide, Adelaide, 5005, Australia
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10
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Brooks AF, Abbott B, Arain MA, Ciani G, Cole A, Grabeel G, Gustafson E, Guido C, Heintze M, Heptonstall A, Jacobson M, Kim W, King E, Lynch A, O'Connor S, Ottaway D, Mailand K, Mueller G, Munch J, Sannibale V, Shao Z, Smith M, Veitch P, Vo T, Vorvick C, Willems P. Overview of Advanced LIGO adaptive optics. Appl Opt 2016; 55:8256-8265. [PMID: 27828071 DOI: 10.1364/ao.55.008256] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
This is an overview of the adaptive optics used in Advanced LIGO (aLIGO), known as the thermal compensation system (TCS). The TCS was designed to minimize thermally induced spatial distortions in the interferometer optical modes and to provide some correction for static curvature errors in the core optics of aLIGO. The TCS is comprised of ring heater actuators, spatially tunable CO2 laser projectors, and Hartmann wavefront sensors. The system meets the requirements of correcting for nominal distortion in aLIGO to a maximum residual error of 5.4 nm rms, weighted across the laser beam, for up to 125 W of laser input power into the interferometer.
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11
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Harris L, Clark M, Veitch P, Ottaway D. Compact cavity-dumped Q-switched Er:YAG laser. Opt Lett 2016; 41:4309-4311. [PMID: 27628384 DOI: 10.1364/ol.41.004309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We report a compact cavity-dumped Q-switched Er:YAG laser that produces pulses with 4.5 ns full width at half-maximum duration and 10 mJ energy. To the best of our knowledge, the resulting 2 MW peak power is the highest reported to date from a 1645 nm Er:YAG laser.
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12
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Abstract
A cryogenic slab laser that is suitable for scaling to high power, while taking full advantage of the improved thermo-optical and thermo-mechanical properties of Yb:YAG at cryogenic temperatures is described. The laser uses a conduction cooled, end pumped, zigzag slab geometry resulting in a near diffraction limited, robust, power scalable design. The design and the initial characterization of the laser up to 200W are presented.
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Affiliation(s)
- Miftar Ganija
- School of Chemistry and Physics and IPAS, The University of Adelaide, SA 5005, Australia.
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13
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Wu KS, Ottaway D, Munch J, Lancaster DG, Bennetts S, Jackson SD. Gain-switched holmium-doped fibre laser. Opt Express 2009; 17:20872-20877. [PMID: 19997323 DOI: 10.1364/oe.17.020872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We demonstrate the first gain-switched, singly doped, single-mode holmium-doped silicate glass fibre laser that operates at 2.106 microm. Using a gain-switched 1.909-microm thulium-doped fibre laser as the pump source, output pulses of energy 3.2 microJ and pulse duration of 150 ns were generated at 80 kHz and slope efficiency of 44%. Pulse stacking within the holmium-doped fibre laser resulted in significantly shorter 70 ns pulses.
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Affiliation(s)
- Ka S Wu
- Institute for Photonics and Advanced Sensing, School of Chemistry & Physics, The University of Adelaide, Adelaide, SA 5000, Australia.
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14
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Corbitt T, Wipf C, Bodiya T, Ottaway D, Sigg D, Smith N, Whitcomb S, Mavalvala N. Optical dilution and feedback cooling of a gram-scale oscillator to 6.9 mK. Phys Rev Lett 2007; 99:160801. [PMID: 17995232 DOI: 10.1103/physrevlett.99.160801] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2007] [Indexed: 05/25/2023]
Abstract
We report on the use of a radiation pressure induced restoring force, the optical spring effect, to optically dilute the mechanical damping of a 1 g suspended mirror, which is then cooled by active feedback (cold damping). Optical dilution relaxes the limit on cooling imposed by mechanical losses, allowing the oscillator mode to reach a minimum temperature of 6.9 mK, a factor of approximately 40 000 below the environmental temperature. A further advantage of the optical spring effect is that it can increase the number of oscillations before decoherence by several orders of magnitude. In the present experiment we infer an increase in the dynamical lifetime of the state by a factor of approximately 200.
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Affiliation(s)
- Thomas Corbitt
- LIGO Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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15
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Corbitt T, Chen Y, Innerhofer E, Müller-Ebhardt H, Ottaway D, Rehbein H, Sigg D, Whitcomb S, Wipf C, Mavalvala N. An all-optical trap for a gram-scale mirror. Phys Rev Lett 2007; 98:150802. [PMID: 17501333 DOI: 10.1103/physrevlett.98.150802] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2007] [Indexed: 05/15/2023]
Abstract
We report on a stable optical trap suitable for a macroscopic mirror, wherein the dynamics of the mirror are fully dominated by radiation pressure. The technique employs two frequency-offset laser fields to simultaneously create a stiff optical restoring force and a viscous optical damping force. We show how these forces may be used to optically trap a free mass without introducing thermal noise, and we demonstrate the technique experimentally with a 1 g mirror. The observed optical spring has an inferred Young's modulus of 1.2 TPa, 20% stiffer than diamond. The trap is intrinsically cold and reaches an effective temperature of 0.8 K, limited by technical noise in our apparatus.
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Affiliation(s)
- Thomas Corbitt
- LIGO Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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16
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Ottaway D, Betzwieser J, Ballmer S, Waldman S, Kells W. In situ measurement of absorption in high-power interferometers by using beam diameter measurements. Opt Lett 2006; 31:450-2. [PMID: 16496883 DOI: 10.1364/ol.31.000450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
We present a simple technique to make in situ measurements of the absorption in the optics of high-power laser interferometers. The measurement is particularly useful to those commissioning large-scale high power optical systems.
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Affiliation(s)
- David Ottaway
- LIGO Laboratory, Massachusetts Institute of Technology, MIT NW17-161, 175 Albany Street, Cambridge, Massachusetts 02139, USA.
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17
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Lawrence R, Ottaway D, Zucker M, Fritschel P. Active correction of thermal lensing through external radiative thermal actuation. Opt Lett 2004; 29:2635-2637. [PMID: 15552669 DOI: 10.1364/ol.29.002635] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Absorption of laser beam power in optical elements induces thermal gradients that may cause unwanted phase aberrations. In precision measurement applications, such as laser interferometric gravitational-wave detection, corrective measures that require mechanical contact with or attachments to the optics are precluded by noise considerations. We describe a radiative thermal corrector that can counteract thermal lensing and (or) thermoelastic deformation induced by coating and substrate absorption of collimated Gaussian beams. This radiative system can correct anticipated distortions to a high accuracy, at the cost of an increase in the average temperature of the optic. A quantitative analysis and parameter optimization is supported by results from a simplified proof-of-principle experiment, demonstrating the method's feasibility for our intended application.
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Affiliation(s)
- Ryan Lawrence
- Department of Physics, Massachusetts Institute of Technology, 175 Albany Street, Cambridge, Massachusetts 02139, USA.
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18
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Abstract
A high-power, low-noise photodetector, in conjunction with a current shunt actuator, is used in an ac-coupled servo to stabilize the intensity of a 10-W cw Nd:YAG laser. A relative intensity noise of 1 x 10(-8) Hz(-1/2) at 10 Hz is achieved.
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Affiliation(s)
- Jameson Rollins
- LIGO Laboratory, Massachusetts Institute of Technology, MIT NW17-161, 175 Albany Street, Cambridge, Massachusetts 02139, USA
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19
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Goda K, Ottaway D, Connelly B, Adhikari R, Mavalvala N, Gretarsson A. Frequency-resolving spatiotemporal wave-front sensor. Opt Lett 2004; 29:1452-1454. [PMID: 15259710 DOI: 10.1364/ol.29.001452] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We report on a high-resolution wave-front sensor that measures the complete spatial profile of any frequency component of a laser field containing multiple frequencies. This probe technique was developed to address the necessity of measuring the spatial overlap of the carrier field with each sideband component of the field exiting the output port of a gravitational-wave interferometer. We present the results of an experimental test of the probe, where we were able to construct the spatial profile of a single radio-frequency sideband at the level of -50 dBc.
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Affiliation(s)
- Keisuke Goda
- LIGO Laboratory, Massachusetts Institute of Technology, NW17-161, Cambridge, Massachusetts 02139, USA
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