11/08/15 – The Path to 3D Integrated Photonics: If You Build It, He Will Come
The challenges encountered by 3D laser written integrated photonics are both cultural and technical in nature. In this talk we will comment on the former, review the latter and highlight new 3D enabled applications.
18/08/15 – Half a Century of Research in Molecular and Optical Physics
August 2015 marks 50 years since I sailed off to commence my PhD studies at U ofBristol in England, so it is timely to present some personal reminiscences, strategic insights and scientific developments to which that has led. I have been lucky to work in various
lively research communities, ranging from U of Sydney, thence to Bristol and NRCC Ottawa, then >45 years as an academic and researcher at UNSW and Macquarie U. My scientific narrative will show the key roles played by curiosity (motivating scientific discovery), capability (experimental and theoretical
tools needed) and continuity (how one thing can lead to another). I intend to cover a wide range of research topics: how electro-optic measurements led me into the emerging fields of nonlinear optics and laser-based experiments; understanding molecular and optical processes in terms of statistical mechanics
(both classical and quantum); facing the intricacies of atomic and molecular spectroscopy; time-resolved optical double-resonance investigations of spectroscopy and energy-transfer processes in small (but not so simple!) polyatomic molecules; developing optical parametric oscillators and cavity-enhanced
spectroscopy (e.g., cavity ringdown) for industrial, environmental, agricultural and biomedical optical sensing; and so on…
25/08/15 – Physicochemical Aspects of Laser Generated Nanostructures and some Applications
In this talk I will discuss physicochemical aspects and control strategies of laser generated nanostructures, in both top down and bottom up approaches. Secondly, I will present new methodologies that we have developed for in situ determination of the processes of
laser induced growth and self-assembly, including the diagnostic of complex laser ablation plasmas by nonlinear optical processes.
01/09/15 – Quantum Physics and Precision Measurement with Ultracold Atoms
Australian National University
The ability to confine and control atoms with great precision has enabled the creation of atomic ensembles at extremely low temperatures. The de Broglie waves of these atoms can overlap to form a Bose-Einstein condensate whose matter-wave properties
can be used to probe fundamental quantum mechanical phenomena. We use helium atoms in the metastable 23S state to enable single atom detection from ultracold atomic clouds, thereby allowing measurement of quantum statistical properties as a probe of matter-wave coherence. The inherent isolation
from the atom’s surroundings also enables precision measurement of atomic structure to test quantum electrodynamics. This presentation will outline breakthroughs in both quantum physics and precision measurement enabled by such exquisite atomic control.
08/09/15 - Revisiting the Morphology-Density Relation for Early Type Galaxies
University of Oxford
Results on the kinematics and scaling relations of early type galaxies throw doubt on our ability to unambiguously identify disks in early type galaxies, and therefore separate elliptical and lenticular galaxies in a physical way. In contrast, velocity fields
provide a clear physical distinction between galaxies on the basis of a proxy for angular momentum. These results have implications for the morphology-density relation of galaxies, and for ideas about how early type galaxies assemble. I will report new results on integral field surveys of galaxies in
clusters that significantly extend the range of local densities that have been explored to test whether the morphology-density relation remains valid.
29/09/15 - Archeology of Massive Galaxies
Australian Astronomical Observatory
I will present research digging up the history of the most massive galaxies in the Universe, many hundreds of times the mass of the Milky Way. Current models cannot explain their growth, but novel observations of their internal motions provide
a different perspective on this puzzle, providing a new baseline for the models to reproduce.
06/10/15 - Nanodiamond: BioPhotonic and Hybrid-Photonic Applications
Fluorescent nanodiamonds (NDs) have a range of unique properties which make them highly desirable for bioimaging and biosensing applications. Their fluorescence is produced via optical excitation of atomic defects, such as the negatively charged nitrogen vacancy centre, within
the diamond crystal lattice. Possessing long-wavelength emission, high brightness, no photobleaching, no photoblinking, single photon emission at room temperature, nanometer size, biocompatibility, and an exceptional resistance to chemical degradation make NDs almost the ideal fluorescent bioimaging
nanoprobe. I will discuss these exciting properties in detail and also give some examples of their integration with photonic materials for hybrid ND-biophotonic applications. In addition, I will discuss details of the research activities at the RMIT node of the ARC Centre of Excellence for Nanoscale
13/10/15 - Gas in Galaxies: The View From Cosmological Hydro-Dynamic Simulations
Observations of the gas content of galaxies are becoming common place, with thousands of galaxies at a wide range of cosmic epochs being studied. This has pushed galaxy formation simulations to start addressing how the different phases of the gas inside and outside galaxies
correlate with other galaxy properties, and how they evolve in the cosmological context. I will show how modern cosmological simulations of galaxy formation attempt to bring together various pieces of observational evidence, and highlight how we are treating this problem using the state-of-the-art EAGLE
20/10/15 - Diamond Based Quantum Technologies
I will discuss recent developments transforming quantum control tools into quantum technologies based on single nitrogen-vacancy (NV) centres in diamond. I will present ultrasensitive MRI at nanoscale and recently developed magnetometry protocols that use quantum
error correction as a resource. Experiments with novel colour centres including silicon-vacancy (SiV) and dinitrogen-vacancy (H3) defects will also be presented.
03/11/15 – Challenges of Fibre-Based Imaging
Fluorescence microscopy has emerged as a pivotal platform for imaging in the life sciences. In recent years, the overwhelming success of its different modalities has been accompanied by various efforts to carry out imaging deeper inside living tissues.
This is motivated by the desire to better understand cellular processes in their natural environment, fully exposed to complex interactions with the living organism they are part of. A key challenge of these efforts is to overcome scattering and absorption of light in tissues. Multiple strategies
(e.g. multi-photon, wavefront correction techniques) extended the penetration depth to the current state-of-the-art of about 1000 um at the resolution of approximately 1um. The only viable strategy for imaging deeper than this is by employing a fibre bundle based endoscope. However, such devices
lack resolution and have a significant footprint (1mm in diameter), which prohibits their use in studies involving e.g. the brains of live animals.
We have recently demonstrated a radically new approach that delivers the light in/out of the place of interest through an extremely thin (tens of microns in diameter) cylindrical glass tube called a multimode optical fibre. Not only is this type of delivery much less invasive compared to fibre
bundle technology, it also enables higher resolution and has the ability to image at any plane behind the fibre without any auxiliary optics. The two most important limitations of this exciting technology are (i) the lack of bending flexibility and (ii) high demands on computational power,
making the performance of such systems slow. I will discuss how to overcome these limitations.
17/11/15 – Nonequilibrium Thermodynamics of Quantum Fluids of Light
Institut Neel, Grenoble
For semiconductor optical microcavities in the so-called ‘strong-coupling regime’, the elementary excitations are cavity-photons strongly dressed by an electronic transitions, so-called quantum-well excitons. These polaritons behave very much
like interacting photons. While their photonic nature provides them with a non-zero effective mass, their excitonic component leads to polariton interactions. As a result, polaritons behave like a highly dissipative quantum fluid of light. In this talk, I will first give a brief review on the superfluid
properties of polaritons and the condensation phenomenon that has been demonstrated ten years ago. In the second part, I will then present recent results obtained in our group that are focused on their thermodynamical properties, showing that despite their highly nonequilibrium character, polariton fluids
manage heat transport in interesting and unusual ways.
24/11/15 – Astrochemistry: Molecules in Space
University College London
It is now well established that chemistry in our Milky Way, as well as in external galaxies, is rich and complex. In this talk I will give an overview of the field of Astrochemistry. I will show how molecules from our own Galaxy, as well as other galaxies,
play a key role in the formation and shaping of such galaxies. By using examples from different regions of space, from interstellar and star-forming gas in the Milky Way, to extragalactic star forming regions, I will demonstrate how important molecules are for our understanding of star and galaxy formation.
15/12/15 – The Puzzle of the Stellar Initial Mass Function
Australian Astronomical Observatory
The stellar initial mass function (IMF) describes the mass distribution of stars produced in an episode of star formation. The IMF links star formation and evolution to galaxy formation and evolution, bridging two research communities, and underpinning
a broad swath of astrophysics. Surprisingly, this fundamental property is rather less well-understood than often assumed over the past sixty years. Apart from the Milky Way and a few nearby galaxies, it is not possible to measure the IMF directly through counts of resolved stars. Consequently, since
it was first measured by Edwin Salpeter in 1955, the IMF has been assumed to be universal and unchanging. Studies over the past few years, though, have challenged this assumption. Numerous approaches to indirectly measure the IMF in distant galaxies provide evidence that it differs between galaxies and
as a function of time, but with strongly conflicting results about the nature of the difference. I will review this recent work, and present an opportunity to self-consistently apply many of these different approaches. This opportunity exploits large-scale galaxy surveys and detailed observations within
the Milky Way, combined with numerical and semi-analytic modelling, to resolve the puzzle of the IMF and provide a robust foundation to all aspects of the field of star formation in the Universe.