ORCID Profile
0000-0001-9303-9307
Current Organisation
Australian National University
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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.
Atomic And Molecular Physics | Atomic, Molecular, Nuclear, Particle and Plasma Physics | Degenerate Quantum Gases and Atom Optics | Quantum Optics And Lasers | Quantum Physics | Theoretical Physics | Optical Physics | Interdisciplinary Engineering not elsewhere classified | Statistics | Engineering not elsewhere classified | Instruments And Techniques | Optical Physics not elsewhere classified | Knowledge Representation and Machine Learning | Condensed Matter Physics not elsewhere classified | Applied Statistics | Other Engineering | Natural Resource Management | Interdisciplinary Engineering | Technology not elsewhere classified | Optics And Opto-Electronic Physics | Condensed Matter Physics—Structural Properties | Atomic and Molecular Physics
Physical sciences | Scientific instrumentation | Expanding Knowledge in the Physical Sciences | Emerging Defence Technologies | Mineral Exploration not elsewhere classified | Expanding Knowledge in Technology | Telecommunications | Environmental Management Systems | Industrial instrumentation | Medical instrumentation | Mathematical sciences | Aerospace Transport not elsewhere classified | Commercial Energy Conservation and Efficiency | Precious (Noble) Metal Ore Exploration | Mining Land and Water Management |
Publisher: Elsevier BV
Date: 10-2002
Publisher: CSIRO Publishing
Date: 1997
DOI: 10.1071/P96079
Abstract: The total differential scattering cross sections for several important unsaturated hydrocarbon molecules with common atmospheric gases were measured in a crossed molecular beam apparatus. The experiments show quantum interferences which relate to potential energy surface parameters, such as the well depth and radial minimum. The d ing of the quantum features, over contributions from experimental resolutions, provides information on the angular and radial anisotropies present in the potential energy surfaces. We have investigated two areas: (1) the role of the probe partner in determining the interaction strength for a given hydrocarbon target, and (2) the effect of increasing the overall length of the hydrocarbon molecule for a fixed probe. By comparing results for a class of scattering systems, we can identify chemical and physical trends that determine the van der Waals potential energy surfaces of larger molecules. We expect these results to aid in the prediction and interpretation of complementary experimental measurements on the high resolution infrared spectroscopy of weakly bound complexes.
Publisher: American Physical Society (APS)
Date: 21-09-2016
Publisher: American Physical Society (APS)
Date: 27-09-1999
Publisher: IOP Publishing
Date: 24-07-2014
Publisher: Optica Publishing Group
Date: 18-05-2022
DOI: 10.1364/AO.456360
Abstract: This paper describes a filled-aperture coherent beam combining (CBC) system based on locking of optical coherence via single-detector electronic-frequency tagging (LOCSET). The sensing and control architecture is implemented using a field-programmable gate array and high-bandwidth electro-optic phase modulators. The all-fiber optical configuration consists of a narrow linewidth 1560 nm seed laser separated into three channels, each containing 7 W erbium-doped fiber lifiers. The system was demonstrated experimentally, achieving a total stabilized output power of 20 W, a combination efficiency greater than 95%, and an output RMS phase stability of λ / 493 . As this architecture employs an entirely digital sensing and control scheme based on LOCSET, it presents a highly scalable and cost-effective solution for CBC that is wavelength agnostic and can support an arbitrarily large number of channels.
Publisher: American Physical Society (APS)
Date: 11-02-2019
Publisher: IEEE
Date: 2006
Publisher: American Physical Society (APS)
Date: 04-10-2012
Publisher: American Physical Society (APS)
Date: 06-10-2017
Publisher: Springer Science and Business Media LLC
Date: 1998
Publisher: American Physical Society (APS)
Date: 22-04-2003
Publisher: American Physical Society (APS)
Date: 28-01-2013
Publisher: American Physical Society (APS)
Date: 25-10-2004
Publisher: American Physical Society (APS)
Date: 13-04-2006
Publisher: American Physical Society (APS)
Date: 26-04-2005
Publisher: Springer Science and Business Media LLC
Date: 02-1993
DOI: 10.1007/BF00682001
Publisher: American Physical Society (APS)
Date: 25-06-2009
Publisher: American Physical Society (APS)
Date: 02-07-2014
Publisher: IOP Publishing
Date: 06-02-2013
Publisher: WORLD SCIENTIFIC
Date: 12-2005
Publisher: IEEE
Date: 2005
Publisher: The Optical Society
Date: 11-2002
DOI: 10.1364/OL.27.001905
Abstract: We demonstrate novel modulation-free frequency locking of a diode laser, utilizing a simple Sagnac interferometer to create an error signal from saturated-absorption spectroscopy. The interference condition at the output of the Sagnac is strongly affected by the sharp dispersion feature near an atomic resonance. Slight misalignment of the interferometer and subsequent spatially selective, or tilt, detection allows this phase change to be converted into an error signal. Tilt locking has significant advantages over previously described methods, as it requires only a small number of low-cost optical components and a detector. In addition, the system has the potential to be constructed as a plug-and-play fiber-coupled monolithic device to provide submegahertz stability for lasers in the commercial market.
Publisher: Frontiers Media SA
Date: 10-2020
Publisher: The Optical Society
Date: 05-02-2009
DOI: 10.1364/OE.17.002319
Abstract: We present results on a Raman laser-system that resonantly drives a closed two-photon transition between two levels in different hyperfine ground states of (87)Rb. The coupler is based on a novel optical design for producing two phase-coherent optical beams to drive a Raman transition. Operated as an outcoupler, it produces an atom laser in a single internal atomic state, with the lower ergence and increased brightness typical of a Raman outcoupler. Due to the optical nature of the outcoupling, the two-state outcoupler is an ideal candidate for transferring photon correlations onto atom-laser beams. As our laser system couples just two hyperfine ground states, it has also been used as an internal state beamsplitter, taking the next major step towards free space Ramsey interferometry with an atom laser.
Publisher: IOP Publishing
Date: 14-01-2002
Publisher: American Physical Society (APS)
Date: 20-02-2014
Publisher: American Physical Society (APS)
Date: 26-05-2017
Publisher: The Optical Society
Date: 25-04-2014
DOI: 10.1364/OE.22.010642
Publisher: CSIRO Publishing
Date: 2006
DOI: 10.1071/FP05300
Abstract: Despite the obvious benefits of using thermography under field conditions, most infrared studies at the leaf level are generally conducted in the laboratory. One reason for this bias is that accuracy can potentially be compromised in sunlight because reflected radiation from the leaf might affect the calculation of the temperature measurement. We have developed a method for measuring leaf temperature in sunlight by using thermal imagery to generate cooling curves from which the time constant for cooling, τ, can be calculated. The original temperature of the sunlit leaf may be determined by extrapolating backwards in time. In the absence of specular reflection, there is close agreement between the extrapolated sunlit temperature and the sunlit temperature recorded by the camera. However, when reflected radiation is high, the difference between the initial (incorrect) temperature determined from the sunlit image and the temperature extrapolated from the cooling curve can be 2°C. Notably, our results demonstrate a close agreement between the extrapolated sunlit temperature and the temperature of the leaf approximately 1 s after being shaded, suggesting that this shaded image provides a good estimate of the original sunlit temperature. Thus, our technique provides two means for measuring leaf surface temperature in sunlight.
Publisher: American Physical Society (APS)
Date: 18-11-2013
Publisher: American Physical Society (APS)
Date: 21-01-1991
Publisher: The Optical Society
Date: 24-07-2009
DOI: 10.1364/OL.34.002321
Abstract: We observe coherent, cw, 455 nm blue-beam production via frequency upconversion in cesium vapor. Two IR lasers induce strong double excitation in a heated cesium vapor cell, allowing the atoms to undergo a double cascade and produce a coherent, collimated, blue beam copropagating with the two IR pump lasers.
Publisher: AIP Publishing
Date: 06-2010
DOI: 10.1063/1.3430538
Abstract: We describe our experimental setup for creating stable Bose–Einstein condensates (BECs) of R85b with tunable interparticle interactions. We use sympathetic cooling with R87b in two stages, initially in a tight Ioffe–Pritchard magnetic trap and subsequently in a weak, large-volume, crossed optical dipole trap, using the 155 G Feshbach resonance to manipulate the elastic and inelastic scattering properties of the R85b atoms. Typical R85b condensates contain 4×104 atoms with a scattering length of a=+200a0. Many aspects of the design presented here could be adapted to other dual-species BEC machines, including those involving degenerate Fermi–Bose mixtures. Our minimalist apparatus is well suited to experiments on dual-species and spinor Rb condensates, and has several simplifications over the R85b BEC machine at JILA, which we discuss at the end of this article.
Publisher: AIP Publishing
Date: 23-04-2007
DOI: 10.1063/1.2734471
Abstract: The authors have used an electromagnetically induced transparency resonance in rubidium as a dispersive reference to lock the relative frequency of two lasers to the atomic ground-state hyperfine splitting. The beat frequency between the two lasers directly generates a microwave signal at 3.036GHz (Rb85) or 6.835GHz (Rb87). High bandwidth (600kHz) feedback was achieved with only low-frequency (10MHz) electronics using the frequency modulation sideband method. The spectral width of the microwave beat frequency was reduced to less than 1kHz. The technique offers a convenient and low-cost method suitable for many topical two-frequency experiments, including coherent population trapping, slow light, lasing without inversion, and Raman sideband cooling.
Publisher: The Optical Society
Date: 22-08-2008
DOI: 10.1364/OE.16.013893
Abstract: A pulsed atom laser derived from a Bose-Einstein condensate is used to probe a second target condensate. The target condensate scatters the incident atom laser pulse. From the spatial distribution of scattered atoms, one can infer important properties of the target condensate and its interaction with the probe pulse. As an ex le, we measure the s-wave scattering length that, in low energy collisions, describes the interaction between the |F = 1,m(F) = -1) and |F = 2,m(F) = 0) hyperfine ground states in (87)Rb.
Publisher: WORLD SCIENTIFIC
Date: 12-2005
Publisher: Wiley
Date: 02-2012
DOI: 10.1111/J.1469-8137.2012.04058.X
Abstract: Transient lulls in air movement are rarely measured, but can cause leaf temperature to rise rapidly to critical levels. The high heat capacity of thick leaves can d this rapid change in temperature. However, little is known about the extent to which increased leaf thickness can reduce thermal damage, or how thick leaves would need to be to have biological significance. We evaluated quantitatively the contribution of small increases in leaf thickness to the reduction in thermal damage during critically low wind speeds under desert conditions. We employed a numerical model to investigate the effect of thickness relative to transpiration, absorptance and leaf size on damage avoidance. We used measured traits and thermotolerance thresholds of real leaves to calculate the leaf temperature response to naturally occurring variable low wind speed. Our results demonstrated that an increase in thickness of only fractions of a millimetre can prevent excursions to damaging high temperatures. This d ing effect of increased thickness was greatest when other means of reducing leaf temperature (transpiration, reflectance or reduced size) were lacking. For perennial desert flora, we propose that increased leaf thickness is important in decreasing the incidence of extreme heat stress and, in some species, in enhancing long-term survival.
Publisher: Elsevier BV
Date: 09-1997
Publisher: American Physical Society (APS)
Date: 04-05-2007
Publisher: The Optical Society
Date: 13-07-2016
DOI: 10.1364/AO.55.005570
Publisher: Wiley
Date: 27-12-2016
DOI: 10.1111/PCE.12857
Abstract: Laboratory studies on artificial leaves suggest that leaf thermal dynamics are strongly influenced by the two-dimensional size and shape of leaves and associated boundary layer thickness. Hot environments are therefore said to favour selection for small, narrow or dissected leaves. Empirical evidence from real leaves under field conditions is scant and traditionally based on point measurements that do not capture spatial variation in heat load. We used thermal imagery under field conditions to measure the leaf thermal time constant (τ) in summer and the leaf-to-air temperature difference (∆T) and temperature range across laminae (T
Publisher: American Physical Society (APS)
Date: 02-03-1992
Publisher: IOP Publishing
Date: 08-2016
Publisher: Springer Science and Business Media LLC
Date: 06-1993
DOI: 10.1007/BF00125428
Publisher: IOP Publishing
Date: 03-02-2012
Publisher: IOP Publishing
Date: 29-11-2011
Publisher: American Physical Society (APS)
Date: 03-09-2020
Publisher: The Optical Society
Date: 20-05-2006
DOI: 10.1364/AO.45.003415
Abstract: We present the first detector that is capable of recording high-bandwidth atom number density measurements of a Bose-Einstein condensate, with a readout of the data in real time. It is based on a shot-noise-limited unbalanced Mach-Zehnder interferometer designed for a minimally destructive measurement of the atom column density of a Bose-Einstein condensate. The shot-noise limit is reached by phase modulating the laser in one arm and phase locking the interferometer with a second-color laser. The detector is characterized, and its sensitivity for a fractional change in the column density of a Bose-Einstein condensate is calculated. With this detection system it may be possible to implement feedback to stabilize a Bose-Einstein condensate or an atom laser.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 02-2013
Abstract: An atom interferometer and an optical frequency comb measure the Compton frequency of a cesium atom, creating a "clock" that weighs atoms. [Also see Report by Lan et al. ]
Publisher: IOP Publishing
Date: 28-06-2011
Publisher: Springer Science and Business Media LLC
Date: 14-09-2020
DOI: 10.1038/S41598-020-71973-0
Abstract: We numerically demonstrate atomic Fabry–Perot resonances for a pulsed interacting Bose–Einstein condensate (BEC) source transmitting through double Gaussian barriers. These resonances are observable for an experimentally-feasible parameter choice, which we determined using a previously-developed analytical model for a plane matter-wave incident on a double rectangular barrier system. Through numerical simulations using the non-polynomial Schödinger equation—an effective one-dimensional Gross–Pitaevskii equation—we investigate the effect of atom number, scattering length, and BEC momentum width on the resonant transmission peaks. For $$^{85}$$ 85 Rb atomic sources with the current experimentally-achievable momentum width of $$0.02 \\hbar k_0$$ 0.02 ħ k 0 [ $$k_0 = 2\\pi /(780~\\text {nm})$$ k 0 = 2 π / ( 780 nm ) ], we show that reasonably high contrast Fabry–Perot resonant transmission peaks can be observed using (a) non-interacting BECs, (b) interacting BECs of $$5 \\times 10^4$$ 5 × 10 4 atoms with s -wave scattering lengths $$a_s=\\pm 0.1a_0$$ a s = ± 0.1 a 0 ( $$a_0$$ a 0 is the Bohr radius), and (c) interacting BECs of $$10^3$$ 10 3 atoms with $$a_s=\\pm 1.0a_0$$ a s = ± 1.0 a 0 . Our theoretical investigation impacts any future experimental realization of an atomic Fabry–Perot interferometer with an ultracold atomic source.
Publisher: Springer Science and Business Media LLC
Date: 10-1992
DOI: 10.1007/BF00692577
Publisher: American Physical Society (APS)
Date: 29-09-2005
Publisher: IOP Publishing
Date: 08-1999
Publisher: The Optical Society
Date: 12-10-2016
DOI: 10.1364/OL.41.004795
Publisher: Springer Science and Business Media LLC
Date: 05-2000
Publisher: Cambridge University Press (CUP)
Date: 2022
DOI: 10.1017/DCE.2022.5
Abstract: Bayesian optimization (BO) has been a successful approach to optimize expensive functions whose prior knowledge can be specified by means of a probabilistic model. Due to their expressiveness and tractable closed-form predictive distributions, Gaussian process (GP) surrogate models have been the default go-to choice when deriving BO frameworks. However, as nonparametric models, GPs offer very little in terms of interpretability and informative power when applied to model complex physical phenomena in scientific applications. In addition, the Gaussian assumption also limits the applicability of GPs to problems where the variables of interest may highly deviate from Gaussianity. In this article, we investigate an alternative modeling framework for BO which makes use of sequential Monte Carlo (SMC) to perform Bayesian inference with parametric models. We propose a BO algorithm to take advantage of SMC’s flexible posterior representations and provide methods to compensate for bias in the approximations and reduce particle degeneracy. Experimental results on simulated engineering applications in detecting water leaks and contaminant source localization are presented showing performance improvements over GP-based BO approaches.
Publisher: American Physical Society (APS)
Date: 20-01-2010
Publisher: The Optical Society
Date: 02-04-2012
DOI: 10.1364/OE.20.008915
Publisher: Elsevier BV
Date: 08-1990
Publisher: The Optical Society
Date: 25-09-2008
DOI: 10.1364/AO.47.005163
Abstract: We demonstrate modulation-based frequency locking of an external cavity diode laser, utilizing a piezo-electrically actuated mirror, external to the laser cavity, to create an error signal from saturated absorption spectroscopy. With this method, a laser stabilized to a rubidium hyperfine transition has a FWHM of 130 kHz over seconds, making the locked laser suitable for experiments in atomic physics, such as creating and manipulating Bose-Einstein condensates. This technique combines the advantages of low- litude modulation, simplicity, performance, and price, factors that are usually considered to be mutually exclusive.
Publisher: Elsevier BV
Date: 05-1992
Publisher: American Physical Society (APS)
Date: 09-09-2004
Publisher: Springer Science and Business Media LLC
Date: 06-2021
Publisher: Elsevier BV
Date: 02-1991
Publisher: American Physical Society (APS)
Date: 31-07-2008
Publisher: IEEE
Date: 06-2022
Publisher: Springer Science and Business Media LLC
Date: 1997
Publisher: The Optical Society
Date: 26-10-2009
DOI: 10.1364/OE.17.020661
Publisher: AIP Publishing
Date: 08-08-1996
DOI: 10.1063/1.472100
Abstract: We obtain analytic expressions for the zero temperature and finite temperature exchange interaction between two hard sphere fermions bound in a symmetric double-well potential in 1, 2, and 3 dimensions and discuss the effect of dimensionality on the model. The three-dimensional model (due to Zilm/Landesmann) and the two-dimensional model presented here are of relevance to the strongly temperature dependent exchange interaction that has been observed between hydrides bound in metal polyhydride complexes.
Publisher: Springer Science and Business Media LLC
Date: 02-2004
Publisher: IOP Publishing
Date: 08-1999
Publisher: American Physical Society (APS)
Date: 27-04-2010
Publisher: American Chemical Society (ACS)
Date: 1996
DOI: 10.1021/JA952142C
Publisher: American Physical Society (APS)
Date: 26-01-2004
Publisher: American Physical Society (APS)
Date: 21-10-1996
Publisher: American Physical Society (APS)
Date: 20-04-2007
Publisher: IOP Publishing
Date: 03-2014
Publisher: American Physical Society (APS)
Date: 26-11-2018
Publisher: Elsevier BV
Date: 08-2013
Publisher: American Physical Society (APS)
Date: 29-01-2010
Publisher: American Physical Society (APS)
Date: 03-02-2004
Location: United States of America
Start Date: 2008
End Date: 12-2009
Amount: $250,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2010
End Date: 12-2015
Amount: $529,797.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2018
End Date: 12-2020
Amount: $727,900.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2016
End Date: 12-2018
Amount: $397,900.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2006
End Date: 12-2006
Amount: $177,900.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2015
End Date: 12-2017
Amount: $415,500.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2007
End Date: 12-2008
Amount: $220,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2011
End Date: 12-2013
Amount: $340,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 03-2021
End Date: 03-2024
Amount: $558,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2003
End Date: 03-2011
Amount: $16,950,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 08-2020
End Date: 08-2025
Amount: $3,973,202.00
Funder: Australian Research Council
View Funded Activity