Dodd-Walls Symposium 2011
Program and Abstracts
1 General Information
Location Weir House is located on Gladstone terrace, on the Kelburn campus of Victoria University of Wellington. Directoins and maps can be found at: http://www.victoria.ac.nz/weirhouse/about/location.aspx
Internet Wireless internet is available in the sky lounge and the dining hall at Weir House.
Catering during the conference All catering at Weir House will be served in the dining hall. Meal times are as follows: • Breakfast – 7:00 a.m. – 9:00 a.m. • Lunch – 12:30 p.m. – 1:30 p.m. • Dinner – 5:30 p.m. – 6:30 p.m.
Conference Dinner The Conference dinner will be held at the Travelodge Wellington on Thursday 10 February at 7 p.m.
Session and Event Information
Notes to presenters Please see the chair of each session before you are due to give your presentation to organize anything that will be needed.
Poster Presentations Poster boards will be located at Weir house in the Sky lounge. Please put your poster up next to your poster number on the morning of Wednesday 9 February. Poster numbers are in the abstract section of the programme.
2 Invited Speakers
Prof. Benjamin Eggleton
Benjamin Eggleton is an ARC Federation Fellow and Professor of Physics at the University of Sydney and is the Director of the ARC Centre of Excellence for Ultrahigh-Bandwidth Devices for Optical Systems (CUDOS). He obtained the Bachelorʼs degree and Ph.D. degree in Physics from the University of Sydney. In 1996, he joined Bell Laboratories, Lucent Technologies as a Member of Staff and was subsequently promoted to Research Director within the Specialty Fibre Business Division of Bell Laboratories, where he was engaged in forward-looking research supporting Lucent Technologies business in optical fibre devices.
Since 2003, he has been the founding director of CUDOS, Australiaʼs Centre of Excellence in Photonics which spans seven universities and more than 120 researchers. His vision of a photonic chip that will enable the Internet to transfer vast amounts of data with significant energy savings brought together a team of national and international scientists that achieved world-first demonstrations of photonic-chip-based ultrafast photonic processing.
Eggleton has published more than 270 journal publications, including articles in Nature Photonics, Nature Physics, Physical Review Letters and he has filed over 35 patents. He is a Fellow of the Optical Society of America, IEEE and the Australian Academy of Technological Sciences and Engineering (ATSE). Eggleton has received numerous awards for his contributions, including the 2010 Scopus Young Researcher of the year award in the Physical Sciences category, the 2008 NSW Physicist of the Year medal, the 2007 Pawsey Medal from the Australian Academy of Science, the 2004 Malcolm McIntosh Prize for Physical Scientist of the Year, the 2003 International Commission on Optics (ICO) Prize, the 1998 Adolph Lomb Medal from the Optical Society of America, the Distinguished Lecturer Award from the IEEE/LEOS, and the R&D100 Award. He was President of the Australian Optical Society from 2008-2010 and is Editor for Optics Communications.
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Prof. Allister Ferguson
Professor Allister Ferguson is responsible for all aspects of the University of Strathclydeʼs research and knowledge exchange policy, strategy and governance. He also has responsibility for postgraduate research student matters and overall responsibility for Research Exchange and Knowledge Services. He was appointed Deputy Principal in August 2004. Allister Ferguson was educated at the University of St Andrews, where he obtained his BSc and PhD in physics. After completing his PhD in lasers and nonlinear optics he was awarded a Lindemann Fellowship that enabled him to spend time as a visiting scholar at Stanford University. He has held academic posts at the University of Oxford, where he was a Research Fellow at Merton College, University of Southampton, and in 1989 he took up the Chair of Photonics at the University of Strathclyde. At Strathclyde his research group is active in lasers, nonlinear optics and laser spectroscopy. He founded the Institute of Photonics, where he is the Technical Director, and the Centre for Biophotonics, where he is Associate Director. He is a Fellow of the Institute of Physics, Optical Society of America, Institute of Electrical and Electronics Engineers, Institute for Contemporary Scotland and Royal Society of Edinburgh.
4 Timetable
TUESDAY
Check-in at Weir House. Dinner served from 5.30–6.30 p.m. in the Weir House dining hall.
WEDNESDAY: Weir House
Session 1: Chair – John Harvey
8:50 Opening remarks 10min
9:00 Talk 1 Ben Eggleton, University of Sydney (Invited Speaker): 40min Delivering Photonics to Transform the New Information Age – Smaller, Faster and Energy Efficient
9:40 Talk 2 Rainer Leonhardt, DWC, University of Auckland: THz 20min research at the University of Auckland
10:00 Talk 3 Claude Aguegaray, DWC, University of Auckland: 20min Similariton propagation and break-up with third-order dispersion
10:20 Talk 4 Stuart Murdoch, DWC, University of Auckland: 20min Measurement of the spectral amplitude and phase of periodic optical signals
10:40–11:10 Coffee break (30 min)
Session 2: Chair – Rob Ballagh
11:10 Talk 5 Joachim Brand, Massey University (Invited Speaker): 20min Dark solitons in superfluid Fermi gases
11:30 Talk 6 Niels Kjaergaard, DWC, University of Otago: From 20min ASTRID to lHC
11:50 Talk 7 David Hutchinson, DWC, University of Otago: Physics 20min of the Riemann hypothesis
12:10 Talk 8 Igor Meglinski, DWC, University of Otago: Biophotonics 20min computational research tool
Lunch served from 12:30–1:30 p.m. in the Weir House dining hall.
5 Session 3: Chair – Howard Carmichael
1:30 Talk 9 Charles Rohde, DWC, University of Auckland: Altering 20min reflectivity through nanoscale laser-induced pattern formation on nickel films
1:50 Talk 10 Brett Telfer, Industrial Research Ltd, Wellington (Invited 20min speaker): Photonics research at IRL
2:10 Group The Dodd-Walls Centre - Strategic Direction 80min Discussion Chair: Crispin Gardiner DWC PIʼs & Invitees
3:30– Coffee break
3:30 Poster To be held in the Sky Room 90min Session
Dinner served from 5:30–6.30 p.m. in the Weir House dining hall.
THURSDAY: Weir House
Session 4: Chair – David Hutchinson
9:00 Talk 1 Allister Ferguson, University of Strathclyde (Invited 40min Speaker): Photonics and innovation in Scotland
9:40 Talk 2 John Harvey, DWC, University of Auckland: Parametric 20min frequency conversion of optical data streams
10:00 Talk 3 Jevon Longdell, DWC, University of Otago: Quantum 20min optics and sensing with cryogenic rare earth ion dopants
10:20 Talk 4 Scott Parkins, DWC, University of Auckland: Cavity QED 20min in cascaded microtoroidal resonators
10:40–11:10 Coffee break (30 min)
6 Session 5: Chair – Rainer Leonhardt
11:10 Talk 5 Tzahi Grunzweig, DWC, University of Otago: Consistent 20min preparation of a single trapped atom
11:30 Talk 6 Howard Carmichael, DWC, University of Auckland: 20min Ground-state quantum beats seen in spontaneous emission: Evolution of coherence through quantum jumps
11:50 Talk 7 Blair Blakie, DWC, University of Otago: Not so ultra-cold 20min
12:10 Talk 8 Dipankar Das, DWC, University of Otago: High precision 20min measurement of 1270nm transition in O2
Lunch served from 12.30-1.30 in the Weir House dining hall.
Session 6: Chair – Igor Meglinski
1:30 Talk 9 Stephane Coen, DWC, University of Auckland: Temporal 20min cavity solitons and symmetry breaking instability in externally driven passive fibre resonators
1:50 Talk 10 Maarten Hoogerland, DWC, University of Auckland: 20min High resolution spectroscopy in helium
2:10 Talk 11 Andrew Hilliard, DWC, University of Otago: Parametric 20min excitation of atoms in an optical micro-trap
Afternoon free
7:00 Dinner for all Symposium attendees at Travelodge
FRIDAY morning
A second meeting will be held for DWC Principal Investigators in Weir House Common Room, followed by lunch. An agenda will be distributed at the Symposium.
7 Abstracts
Oral Presentations
Wednesday
Talk 1 (Invited): Delivering Photonics to Transform the New Information Age – Smaller, Faster and Energy Efficient Benjamin Eggleton School of Physics, University of Sydney Director, CUDOS ARC Centre of Excellence Institute of Photonics and Optical Science
The importance to 21st-century economies of a fast and efficient Internet was acknowledged in 2009 by the Australian Government’s decision to build the National Broadband Network (NBN). The key technology behind the Internet is photonics—the science of generating, transmitting, processing and detecting light. Going far beyond the optical fibres which merely transfer light, photonics has the capability to transform all areas of modern society that rely on information transfer. In biology, photonics interrogates molecular structures and can provide information critical to human health and environmental sustainability; photons from distant galaxies carry information that can reveal the origins of the Universe; and the quantum properties of photons promise new information systems with impenetrable security.
Photonic signal processing is the key to opening up technological opportunities in all of these areas. CUDOS has played a pivotal role in demonstrating ground breaking integrated photonic signal processors that can massively increase the information capacity of the Internet, bringing us within reach of breathtaking capabilities that will transform almost every facet of the information society and economy.
This major advance in bandwidth is the first of three essential goals we must achieve for photonics to become the defining technology for the coming century. The second challenge is to miniaturise photonic devices so they can be incorporated into more complex circuits, bringing increased functionality, cost-efficient manufacture and widespread application. Our third goal is to make photonic processors energy-efficient, to restrain the increasing amounts of energy consumed by the Internet.
Talk 2: THz research at the University of Auckland Jess Anthony and Rainer Leonhardt DWC, University of Auckland
As we measure the electric field of the THz radiation in our THz set-up, the results can be used to determine the losses and the dispersion properties of solid-core and air-core micro-structured fibers.
8 Talk 3: Similariton propagation and break-up with third-order dispersion Claude Aguegaray DWC, University of Auckland
We present a novel analytical solution and the conditions leading to accurate description of propagating pulses and critical length describing pulse break-up for the generalized non-linear Schrödinger equation with third-order fiber dispersion and constant gain.
Talk 4: Measurement of the spectral amplitude and phase of periodic optical signals Stuart Murdoch DWC, University of Auckland
We present a heterodyne measurement capable of determining the spectral amplitude and phase of a periodic optical signal at repetition rates up to 100 GHz. The measurement requires no external electronic clock to operate. Measurements of free-running 40 GHz quantum-dash modelocked laser diodes will be presented.
Talk 5: (Invited) Dark solitons in superfluid Fermi gases Joachim Brand and Renyuan Liao New Zealand Institute for Advanced Study and Centre for Theoretical Chemistry and Physics, Massey University, Auckland
Dark solitons are coherently propagating nonlinear waves that are characterised by the localised absence of a background medium, which could be light (dark spot) or a matter-wave field (rarefaction pulse). Here, we show that families of dark solitons characterised by their propagation velocity exist in superfluid Fermi gases. The energy-velocity dispersion and number of depleted particles completely determines the dynamics of dark solitons on a slowly-varying background density. For the unitary Fermi gas we determine these relations from general scaling arguments and conservation of local particle number. We predict solitons in a trapped Fermi gas to oscillate sinusoidally at the trap frequency reduced by a factor of 1 3 . Numerical integration of the time-dependent Bogoliubov-de Gennes equation determines spatial profiles and soliton dispersion relations across the BEC-BCS crossover and proves consistent with the scaling relations at unitarity.
Talk 6: ! From ASTRID to lHC Niels Kjaergaard DWC, University of Otago
This talk will describe an odyssey from laser-cooled ions in a large scale accelerator to the table top size collider for ultracold atoms currently under construction at Otago.
9 Talk 7: Physics of the Riemann hypothesis Daniel Schumayer and David A.W. Hutchinson DWC, University of Otago
We consider the Riemann zeta function and examine its influence in the realm of physics and also how physics may be suggestive for the resolution of one of mathematics' most famous unconfirmed conjectures, the Riemann Hypothesis. Does physics hold an essential key to the solution for this more than hundred-year-old problem? We examine numerous models from different branches of physics, where this function plays an integral role. Throughout these examinations we highlight how physics can perhaps shed light on the Riemann Hypothesis.
Talk 8: Biophotonics computational research tool Igor Meglinski DWC, University of Otago
Utilizing various feature of light optical and laser-based modalities are able to provide effective solutions in a range of practical applications. We introduce a novel computational tool for biophotonics and optical diagnostics needs.
Talk 9: Altering reflectivity through nanoscale laser-induced surface pattern formation on nickel films Charles Rohde DWC, University of Auckland
In this talk I will discuss our investigations into the effects of laser-induced pattern (LISP) formation on the absorption properties of nickel-plated surfaces. We employed a chirped-pulse, amplified laser system (Coherent Legend Elite) to generate linearly polarized 100fs pulses centred at 800nm with a 1kHz repetition rate. We machined 5mm x 5mm regions of electrolessly plated-nickel with a hexagonal close packed array of 10µm diameter holes. This resulted in nano-pattered, micon-scale surface indentations of controllable depth. The geometry of the resulting surfaces were examined with scanning electron microscopy and the surface reflectivity of these samples investigated as a function of specular reflection angle and machining power with a custom built, angle-resolved spectrometer.
Talk 10: (Invited) Photonics research at IRL Brett Telfer Industrial Research Ltd, Wellington
10 Thursday
Talk 1 (Invited): Photonics and innovation in Scotland Allister Ferguson Institute of Photonics University of Strathclyde, Glasgow, Scotland
Talk 2: Parametric frequency conversion of optical data streams John Harvey DWC, University of Auckland
Talk 3: Quantum optics and sensing with cryogenic rare earth ion dopants Jevon Longdell DWC, University of Otago
I will give an overview of progress of the three projects currently underway in my lab: the optical detection of ultrasound, the generation of broadband time-delayed entanglement, and cavity QED using whispering gallery mode resonators.
Talk 4: Cavity QED in cascaded microtoroidal resonators Scott Parkins DWC, University of Auckland
We examine the spontaneous emission properties of atoms coupled to two-way cascaded microtoroidal resonators and uncover a novel dependence of effective atom-atom interactions on the atom-cavity detuning.
Talk 5: Consistent preparation of a single trapped atom Tzahi Grunzweig DWC, University of Otago
We induce light-assisted collisions between neutral atoms trapped in an optical microtrap to isolate a single atom. Our resulting 82.7% loading efficiency solves a major obstacle in using single atoms for quantum information processing devices.
11 Talk 6: Ground-state quantum beats seen in spontaneous emission: Evolution of coherence through quantum jumps H.J. Carmichael DWC, University of Auckland D. Norris, L.A. Orozco Joint Quantum Institute, University of Maryland and NIST P. Barberis-Blostein Instituto de Investicación en Matemáticas Aplicadas y en Sistemas, Universidad Nacional Autónoma de México
An experiment realizing spontaneously created ground-state quantum beats is described and modeled using quantum trajectories. The beats recover quantum coherence from quantum noise. Their frequency shifts with increasing drive intensity in the opposite direction to a light shift. An explanation from quantum jumps is given.
Talk 7: Not so ultra-cold Blair Blakie DWC, University of Otago
I will discuss recent work in my group on "warm" ultra-cold gases. This will include work on coherence in strongly correlated bosonic Mott insulators, the properties of dipolar gases, and highly non-equilibrium dynamics of an atomic collider.
Talk 8:
High precision measurement of 1270nm transition in O2 Dipankar Das DWC, University of Otago High precision spectroscopic measurement of atomic and molecular energy levels played a very important role in the development of many branches of physics. Precise measurement of the ultra- weak absorption bands of molecular oxygen, so-called oxygen atmospheric band are of importance of understanding and modeling the Earth’s atmosphere. Measurements on the oxygen A band are of very importance to determine the altitude varying, temperature and pressure profiles of the Earth’s atmosphere. In this work we have used two highly sensitive spectroscopy techniques of absorption spectroscopy; cavity ring-down spectroscopy (CRDS) and noise-immune cavity enhanced optical 1 3 heterodyne molecular spectroscopy (NICE-OHMS) to measure the a ∆g ←X ∑g transition at 7882.39 cm-1 (1270nm).
Talk 9: Temporal cavity solitons and symmetry breaking instability in externally driven passive fibre resonators Stephane Coen DWC, University of Auckland
In this talk, we will first review the properties of temporal cavity solitons, which are pulses that propagate indefinitely in passive fibre resonators. We will then describe a symmetry breaking instability that can occur in the same system, and how this is related to cavity solitons. Preliminary experimental results will be discussed.
12 Talk 10: High resolution spectroscopy in helium Maarten Hoogerland DWC, University of Auckland
Accurate spectroscopy in helium is important to verify our model of the atom. I will present results on high-resolution spectroscopy on the triplet to singlet metastable state transition in helium. The 8 Hz natural linewidth allows us to make measurements accurate to about 5 kHz on the 1557 nm transition.
Talk 11: Parametric excitation of atoms in an optical micro-trap Andrew Hilliard DWC, University of Otago
We trap a controlled number of atoms in an optical micro-trap and drive the trapping potential parametrically. The initial number of atoms in the trap is varied from one to 50. When only one atom is present in the trap, we observe excellent agreement with a single particle model predicting strong trap dependent resonances in the energy absorbed by the atoms. When more atoms are introduced to the trap, we observe a transition to a strongly damped regime where the trap dependent resonances vanish. This experimental realization of a driven mesoscopic system may provide an exciting platform for the study of irreversible processes in isolated systems.
13 Poster Presentations
Poster 1: Progress towards using partial wave scattering for analysing Feshbach resonances Ana Rakonjac DWC, University of Otago
As an external magnetic field approaches a Feshbach resonance, the scattering length of interacting atoms approaches infinity, strongly altering their behaviour. Most methods for characterising Feshbach resonances rely on measuring loss of atoms due to increased collision rates or radio frequency spectroscopy of molecules formed by magnetic association. We propose a new method for analysing Feshbach resonances by directly imaging partial wave interference patterns from two ultracold atom clouds in an optical collider and extracting the scattering length. The optical collider is a double cross- dipole trap that accelerates two ultracold clouds towards one another and allows full control over the collision energy.
Poster 2: High power fiber optical parametric oscillator Y. Q. Xu, K. F. Mak and S. G. Murdoch DWC, University of Auckland
We present a high power fiber parametric oscillator, which is tunable over 450 nm, with 0.5 nm linewidth output. The sidebands have average output powers in excess of 4 W between 1580 and 1680 nm, and in excess of 2 W out to 1780 nm.
Poster 3: Squeezing on the two-photon resonance in strongly coupled cavity QED Joseph Nelson DWC, University of Auckland
We consider the open Jaynes–Cummings model driven on the two–photon resonance, in the regime of very strong coupling. The possibility of finding squeezed light in the cavity output field is then explored quantitatively, through numerical simulations and an analytic model of the system.
Poster 4: Dynamic effects of a Feshbach resonance on Bragg scattering from a Bose-Einstein condensate Catarina E. Sahlberg, R. J. Ballagh and C. W. Gardiner DWC, University of Otago
We present a theoretical model for Bragg scattering from a Bose-Einstein condensate close to a magnetic Feshbach resonance, using a classical field Projected Gross-Pitaevskii formalism and explicitly including the dynamics of the resonance.
14 Poster 5: Quantum tunneling of a vortex O. Fialko and J. Brand Massey University
It has been a subject of long debates whether a vortex may exhibit quantum mechanical aspects like quantum tunneling between two pinning potentials. We show that the vortex indeed tunnels with the tunneling rate much higher than the previous studies suggest, making possible its experimental realization.
Poster 6: Time delay in stochastic electrodynamics S. J. Whalen, M. J. Collett, A. S. Parkins and H. J. Carmichael DWC, University of Auckland
Stochastic electrodynamics (SED) is a hidden variables theory which reproduces the predictions of quantum mechanics in the semiclassical limit where the Wigner function is positive-semidefinite. We consider a model within SED involving feedback with time delay, and derive properties of the steady state.
Poster 7: The dynamics of vortices in dilute Bose-Einstein condensates at finite temperature B.G. Wild and D.A.W. Hutchinson DWC, University of Otago
We solve the time-independent Hartree-Fock-Bogoliubov (HFB) equations in the rotating frame to obtain stationary solutions for a precessing vortex in a quasi-two-dimensional Bose Einstein Condensate (BEC). An expression for the precessional frequency is found, and is solved self- consistently with the HFB equations. We find agreement with the predictions of the zero temperature calculations (Bogoliubov approximation), and a smooth variation in the precession frequency as the temperature is increased in the HFB equations. Time-dependent solutions confirm the validity of these precessional frequency predictions.
Poster 8: Emergence of a roton minimum in an interacting BEC S.C. Cormack, D. Schumayer and D.A.W. Hutchinson DWC, University of Otago
An implementation of the path integral Monte Carlo technique is developed with the aim of estimating the excitation spectrum of a Bose-Einstein condensate with particle interactions. The appearance of a roton minimum is observed when the interaction strength is large. This result is examined in relation to the shift in critical temperature of a BEC, due to the particle interactions, predicted elsewhere. An averaging procedure is employed to reduce the error due to finite size effects, and a fit to a trial function is attempted as an alternative to this.
15 Poster 9: Terahertz photonic bandgap fiber Jess Anthony and Rainer Leonhardt DWC, University of Auckland
We measured Kagome microstructured fibers using the THz time domain spectroscopy setup. We observed fundamental mode guidance in the hollow core and the measured data give good agreement with resonance frequencies predicted by antiresonant reflecting optical waveguide (ARROW).
Poster 10: Ultra-cold Bose gas in a disordered 2-D optical lattice Joseph Towers and David Hutchinson DWC, University of Otago
A weak 2D optical lattice is superimposed on ultra-cold Bose atoms in a strong 2D optical lattice, the resulting interferenece creates weak shifts in the well-depth at each lattice site which, although strictly periodic, can seem random to the system under certain conditions. We explore the conditions under which this model leads to Anderson localization.
Poster 11: Vortex dynamics in a warm Bose-Einstein condensate Sam Rooney DWC, University of Otago
We use the stochastic Projected Gross-Pitaevskii equation formalism to investigate the dynamics of a centrally located single vortex for a range of temperatures and condensate geometries.
Poster 12: Finite temperature theory for novel cold gas systems Danny Baillie DWC, University of Otago
The phenomenal recent progress with the control of the external degrees of freedom of ultra-cold gases, and the advent of new species with long-range interactions presents a range of new and exciting systems for exploring many body physics. The mean-field description of these systems is challenging and demands the development of new systematic theoretical approaches that lead to tractable and accurate numerical schemes. In this work we present a range of applications of finite temperature mean-field theory to such systems.
Poster 13: Stability of the dipolar Bose gas Russell Bisset DWC, University of Otago
We implement a Hartree-Fock theory to investigate the stability of dipolar Bose gases near Tc.
16 Poster 14: Calorimetry of Bose-Einstein condensate and Loschmidt cooling Arif Ullah and Maarten Hoogerland DWC, University of Auckland
A Bose-Einstein Condensate (BEC), trapped in a harmonic trap, can be characterized by the total atom number N, the internal energy U and the trap frequency ω. The internal energy has been difficult to measure experimentally with any accuracy. We are presenting some precision calorimetry measurements, finding the internal energy of a Bose-Einstein Condensate as a function of temperature, based on the proposal by Blakie et al. We will also present some of our results with the delta kicked rotor experiments and Loschmidt cooling.
Poster 15: Optical detection of ultrasound using dispersion due to spectral holes Jian Wei Tay, Patrick Ledingham and Jevon Longdell DWC, University of Otago
Poster 16: Ultrafast Laser Studies of the Characteristics and Timescales of Photodegradation in Red Lake Dyes Sarah Thompson, Charles Rohde and Cather Simpson The Photon Factory, University of Auckland
This project exploits the use of ultrafast laser spectroscopy techniques to establish the photodegradation timescales and processes associated with pigments and dyes of importance to the art conservation and restoration community. It is widely recognized that pigments and dyes are photosensitive; these ultrafast spectroscopic studies bridge the fields of art and science to contribute to the preservation of cultural heritage both in New Zealand and internationally, while at the same time working toward a deeper understanding of the fundamental interactions that occur between light and molecular structures.
Poster 17: A New Instrument for Measuring Charge-separated States of Synthetic Solar Energy Harvesting Complexes Julie Kho, Charles Rohde, Peter Boyd, Frederique Vanholsbeeck, and Cather Simpson The Photon Factory, University of Auckland
We have constructed a nanosecond transient absorption instrument and characterized its behaviour in the laboratory setting. The instrument performs with excellent stability and power for measuring photodynamics of solar energy harvesting model complexes. This new laser system is the only one in the world that has the bandwidth, pulsewidth, and stability to probe these important systems with facility.
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