Available Postgraduate Research Projects
The postgraduate programs offered within the Lasers and Photonics CORE at Macquarie University, Sydney will bring the students to the emerging frontiers of research and provide opportunities to make distinctive world-class contributions.in the following five focus areas:
- Biophotonics exploits interactions between light and biological material in a wide variety of applications. Biophotonics is widely recognised as a key science/technology upon which the next generation of clinical tools and biomedical research instruments will be based.
- Microphotonic optical systems manipulate and control light on a microscopic scale and represent a major advance for lasers and optical technology.
- Nano-optics and nanophotonics involves theoretical and experimental nanoscale research into light emission, propagation and interaction with matter, as well as optical properties of materials and structures. It is widely regarded as fertile ground for significant future advances.
- Optical sensing and imaging is relevant to areas such as the environment, community health and safety, defence, information retrieval, and entertainment.
- Ultrafast laser applications include sensing and imaging of biological processes, fabrication of microphotonic devices by lasers, and coherent generation of white-light supercontinua for spectroscopy and imaging.
Research Project descriptions are listed below.
Postgraduate Scholarships
Macquarie University offers postgraduate scholarships for suitably qualified students. Both Australian and overseas students are eligible. The scholarships provide tuition fees and living expenses. For more information about opportunities within the Division of Information and Communication Sciences please visit our website http://www.ics.mq.edu.au/postgrad and follow the link to ICS Postgraduate Research. Please contact ICS Student Services (enquiries@ics.mq.edu.au) if you need assistance with the scholarship or admission procedures.
Research Project Descriptions
- Application of Pulsed Vacuum-Ultraviolet Photon Sources to Surface Science of Glass and Medical Polymers
- Short pulse and Tunable Microchip Lasers
- Photonics using Opals
- Random Lasers
- Nonlinear Device Fabrication in Chalcogenide Glasses
- High Energy Femtosecond Oscillators
- Photonics Device Fabrication
- Nanotechnology Approaches for Optical Sensing of Trace Chemicals - temporarily unavailable until further notice
- Development of Nanoparticles for Fluorescence Labeling by using Laser Ablation - temporarily unavailable until further notice
- Nonlinear Dynamics of Semiconductor Lasers
- Laser Processing for Cultural Heritage Conservation and Public Good Applications
- Particle-Surface Dynamics excited by Pulsed Lasers
- Narrowband Tunable Optical Parametric Oscillators for Spectroscopic Applications
- Coherent Raman Micro-spectroscopy and Imaging
- Novel Techniques for Gas Sensing by Cavity Ringdown Spectroscopy
- Continuous-wave Raman Lasers operating at Yellow and UV Wavelengths
- Diamond-based Single Spin Detector
- Generating Ultra-short Pulses from Raman Lasers
- Tunable Ultraviolet Continuous-wave Laser Sources
- Guided Wave Polymer Optics
- Applications of Multiwavelength Fibre Lasers
- Polymer Fibre Sensors
- Laser Direct Writing of Photonic Devices
- Ultrafast Laser Direct Writing of Multiwavelength Waveguide Lasers
- Background-free optical imaging of tag-free macromolecules
- Application of multiphoton microscopy to study of collagen regeneration
- Application of luminescent nanodiamonds to intracellular imaging
Application of Pulsed Vacuum-Ultraviolet Photon Sources to Surface Science of Glass and Medical Polymers
Dr Robert Carman, Prof Deb Kane
Macquarie University has a patented, platform technology for plasma based, high-peak-power, pulsed vacuum-ultraviolet photon sources which have broad range of application. This project will investigate how the pulse shape and pulse length emitted by a Xenon source at 172 nm affect the surface science of optical material and medical polymer surfaces. The project will involve moderate power scaling of the Xenon plasma-based source and experiment and theory of the photonic/surface interactions that lead to modified surface parameters. These modified surface parameters are predicted to be favourable in many of the commercial applications of the materials investigated.
Contact rcarman@ics.mq.edu.au
Short Pulse and Tunable Microchip Lasers
A/Prof David Coutts, Dr David Spence
Microchip lasers are solid-state lasers where the laser mirrors are directly coated on a thin piece of laser material. Such lasers find many applications e.g. laser ranging, biophotonics, and materials processing. Building upon exciting preliminary results, we propose to study a new class of microchip lasers which is broadly tunable. For example we will use Ti:Sapphire and cerium based laser crystals and incorporate wedge etalon tuning elements. Systems for generating very short pulses (down to few 10's of ps) will also be investigated, including novel master oscillator-power amplifier techniques. We will also use these lasers for nonlinear optics including nonlinear microscopy. The project will involve both experimental and some laser modeling work and would suit a student with an interest in lasers and optics.
Contact dcoutts@ics.mq.edu.au
Photonics Using Opals
A/Prof Judith Dawes, A/Prof Mick Whitford
Photonic crystals are regular structures that can control the propagation of light; for example opals, which reflect different colours of light when viewed in different directions. These may be created in the laboratory by assembling an array of microspheres into a photonic crystal. We have fabricated opals on substrates such as optical fibre to create structures that influence light propagation in optical fibre. Here, in collaboration with the Tyndall Institute in Ireland, we will extend this concept to create photonic devices that can manipulate light within the opal structure by allowing the growth of the opal on patterned substrates.
Contact judith@ics.mq.edu.au
Random Lasers
A/Prof Judith Dawes, Dr Peter Dekker
Random lasers are strongly scattering media with optical gain. While these systems have much in common with standard lasers, they also offer unique possibilities for optical behaviour; for example there is no preferred direction or identified path for laser action and the light propagates by many scattering events. Because the random laser action at surfaces ifs of interest for many applications, we propose to study these lasers and their characteristics using near field optical microscopy to observe the material surface. We will investigate materials including ceramic laser materials to enhance the performance of these lasers and we will compare the experimental and modeled results.
Contact judith@ics.mq.edu.au
Nonlinear Device Fabrication in Chalcogenide Glasses
Dr Alex Fuerbach, A/Prof Mick Withford
The development of a "photonic chip" relies on nonlinear optical effects in order to realise complex functions like all-optical switching. Thus, novel highly nonlinear materials have to be used. Chalcogenides are attractive candidates for this task. The aim of the proposed project is to study fundamental aspects of femtosecond laser processing of these exotic glasses with the goal of eventually fabricating functioning devices. An evanescent coupler is one example of such a device, where an intensity dependent mode diameter due to a corresponding change in the refractive index of the material can give rise to a strong nonlinear coupling behaviour. Beyond, other concepts should also be developed, theoretically analysed and finally realised.
Contact fuerbach@ics.mq.edu.au
High Energy Femtosecond Oscillators
Dr Alex Fuerbach, Dr David Spence
The aim of this project is to investigate methods to generate ultrashort laser pulses at MHz repetition rate with energies approaching the microjoule range. Potential schemes which will be studied include, but are not limited to, extended-cavity oscillators, cavity-dumped systems and/or quasi-continuous wave (cw) amplifiers. Pure Kerr-lens mode-locking (KLM) and the use of saturable Bragg reflectors (SBR) will be compared and investigated theoretically and experimentally and techniques to shorten the achievable pulse duration will be developed. All these approaches rely on a careful dispersion control, an elaborate resonator design and a proper thermal management which are thus crucial for this project.
Contact fuerbach@ics.mq.edu.au
Photonics Device Fabrication
Dr Alex Fuerbach, A/Prof Mick Withford
The aim of this project is to investigate fundamental mechanisms underlying the interaction of femtosecond laser pulses with transparent dielectrics with emphasis on waveguide writing. A femtosecond laser system with a variable repetition rate from single-shot of up to 5 MHz will be used to study the influence the time between successive laser pulses has on the waveguide formation. Technically relevant dielectrics ranging from glasses to ferroelectric crystals will be considered and material specific models will be developed. Aimed with the knowledge about the best methods of producing low-loss high-quality waveguides, functioning photonic devices will be fabricated, characterised and finally tested.
Contact fuerbach@ics.mq.edu.au
Nanotechnology Approaches for Optical Sensing of Trace Chemicals
Prof Ewa Goldys, Dr James Downes
This project will advance a specialised optical sensor technology for rapid detection of trace molecules using custom design of sensing surfaces. The project will focus on increasing sensor sensitivity through
- An electromagnetic effect of surface enhancement
- Substantial increase of surface area though a nanoscale surface profile
- Customisation of the sensor surface for the detection of selected molecules.
The program will comprise elements of optics, optoelectronics engineering and chemical/biological sensing. Through its theoretical component the research will result in a more robust understanding of surface enhancement of surface plasmon-related effects leading to developments of more accurate sensors. For more information see http://www.physics.mq.edu.au/~goldys/core
Contact goldys@ics.mq.edu.au
Development of Nanoparticles for Fluorescence Labeling by Using Laser Ablation
Prof Ewa Goldys, A/Prof Mick Withford
The project will concentrate on the design and fabrication of nanostructured II-VI and III-V hosts doped with rare earth ions customised for the demands of fluorescent labelling. The synthesis will be carried out using femtosecond laser ablation. We will use rare earth doping and co-doping to carry out emission wavelength and lifetime control. We will aim at achieving a single wavelength excitation and identify ways to alter the surface of nanopowders for applications in fluorescence labelling. Characterisation will include microRaman, microfluorescence and electron microscopy. Applications in protein staining are envisaged at the conclusion of the project.
Contact goldys@ics.mq.edu.au
Nonlinear Dynamics of Semiconductor Lasers
Prof Deb Kane, Dr Peter Browne
National and international research collaborations provide the MQU group with state-of-the-art integrated semiconductor quantum dot lasers for our laser nonlinear dynamics research. This project will research the laser dynamics of these novel devices, building on prior research [eg Unlocking Dynamical Diversity: Optical Feedback Effects on Semiconductor Lasers, Eds DM Kane and KA Shore, Wiley and Sons (2005)]. This project will be at the forefront of laser nonlinear dynamics research, internationally. These devices have potential to be developed for applications in, for example, communications and imaging. The project will develop experimental, theoretical and collaborative research skills.
Contact debkane@ics.mq.edu.au
Laser Processing for Cultural Heritage Conservation and Public Good Applications
Prof Deb Kane, Dr Peter Browne
New and modified laser processing techniques continue to be researched for a myriad of applications in industrial, art and cultural heritage conservation, and environmental contexts. This project will research laser processing solutions for several identified problems in Australian Indigenous and Pacific cultural heritage conservation and textile cleaning. All the studies will be completed as quantitative science and can be described as laser-materials interactions. New laser processing solutions will be informed by the detailed scientific understanding gained as the project progresses, The project will develop experimental, theoretical and collaborative research skills.
Contact debkane@ics.mq.edu.au
Particle-Surface Dynamics Excited by Pulsed Lasers
Prof Deb Kane, Dr Peter Browne
Currently, our ability to measure and understand the dynamics of a micro or a nanoparticle on a surface caused by absorption of a pulse of light; in terms of the optics, the temperature and phase changes, the thermoelastics, and the mechanics; all with due attention to differences at the micro/nanoscale compared with the well known macroscale, is in its infancy. The project will make significant development in demonstrating experimental techniques to record the dynamics quantitatively. The aim will also be to decouple components of the dynamics caused by thermal effects from the non-thermal effects. The project will develop experimental, theoretical and collaborative research skills.
Contact debkane@ics.mq.edu.au
Narrowband Tunable Optical Parametric Oscillators for Spectroscopic Applications
Prof Brian Orr, A/Prof David Coutts, Dr Yabai He
We aim to develop innovative wavelength-control methods for optical parametric oscillator, laser and nonlinear-optical devices that emit narrowband tunable coherent light for gas sensing and for high-resolution spectroscopic measurements from the infrared to the vacuum ultraviolet. The narrow spread of wavelengths and high optical power density result in instruments capable of high sensitivity and molecular specificity, to enable advanced spectroscopic sensing of particular gas-phase molecules (e.g., in industrial processes, medical diagnostics, security checks, and the atmosphere). These techniques will also be applied for fundamental quantum-electrodynamic studies and to explore dissociation dynamics and energetics in highly excited molecules.
Contact borr@ics.mq.edu.au
Coherent Raman Micro-spectroscopy and Imaging
Prof Brian Orr, A/Prof David Coutts, Dr Yabai He
Nonlinear-optical processes in intense laser beams enable biological materials (e.g., tissues, cells, biomolecules, chemical media) to be microscopically identified, imaged and characterised. This PhD project aims to advance one such approach - coherent anti-Stokes Raman scattering (CARS) - by improving existing confocal microscopic techniques (e.g., epi-detected CARS microscopy), developing cost-effective laser-based probes (e.g., fibre-optical CARS endoscopy), and discovering new micro-spectroscopic information (e.g., concerning pharmacokinetics of anti-cancer drugs). Such outcomes are in the rapidly expanding area of biophotonics, where physical and optical research can provide innovative tools and fresh insights into key biomedical processes.
Contact borr@ics.mq.edu.au
Novel Techniques for Gas Sensing by Cavity Ringdown Spectroscopy
Prof Brian Orr, A/Prof David Coutts, Dr Yabai He
Cavity ringdown (CRD) spectroscopy is a cavity-enhanced technique that provides very high sensitivity for detection of weak absorption spectra of gas-phase molecules. It measures the decay time of radiation inside an optical cavity, rather than the transmitted optical power or energy as in conventional absorption spectroscopy. Our proposed experiments will use tunable coherent radiation (for example, from a laser or nonlinear-optical source) that may be either pulsed (with high repetition rate for optimal duty factor) or continuous wave (using our innovative rapidly swept CRD techniques). Ongoing research will concentrate on maximising detection sensitivity attainable with compact, cost-effective instrument designs.
Contact borr@ics.mq.edu.au
Continuous-wave Raman Lasers Operating at Yellow and UV Wavelengths
Dr Helen Pask, Prof Jim Piper
Diode-pumped crystalline Raman lasers are practical and efficient sources of laser output at otherwise "hard to reach" wavelengths. They use stimulated Raman scattering (SRS) in nonlinear crystals to shift the output wavelength further into the infrared. When combined with frequency doubling, efficient conversion to many visible and UV wavelengths occurs. Raman lasers are unique in many ways and the physics involved gives rise to interesting and unusual effects. This research project will build on our recent success in developing cw yellow sources for medical, biomedical and remote sensing applications, and will involve a combination of experimental and numerical modeling.
Contact hpask@ics.mq.edu.au
Diamond-based Single Spin Detector
Dr James Rabeau, Prof Jason Twamley
The ability to reliably measure the spin of a single electron will provide a fundamentally new and exciting tool for the study of physical, chemical and biological processes on surfaces and in liquids with a nano-scale resolution. The aim of this project is to develop a diamond based scanning probe capable of making such precision measurements. The probe will operate at room-temperature and have sensitivity down to a single electron spin. Numerous applications exist in electronics fabrication, magnetic memory materials, spintronics and quantum computing, as well as biological applications such as measuring the folding structure of a protein by site selective spin labels.
This program is currently funded under the Australian Research Council, Discovery Projects scheme, and is closely linked to Dr Rabeau's second funded ARC grant "Diamond single photon source". Please go to http://www.ics.mq.edu.au/~jrabeau/ for more information about this research area.
Contact jrabeau@ics.mq.edu.au
Generating Ultra-short Pulses from Raman Lasers
Dr David Spence, Prof Jim Piper
While pulsed Raman lasers often generate short output pulses resembling mode-locked laser output, the process is poorly understood. With the recent advent of continuous-wave crystalline Raman lasers, as well as initial reports of what we interpret as a mode-locked fibre Raman laser, this project will investigate the mechanism for short-pulse formation and mode-locking in Raman lasers. With a combination of experiments on a range of laser systems as well as theoretical work and numerical simulation, we will investigate the fundamental physics that underlies this novel mode-locking mechanism, leading to the generation of new picosecond laser sources.
Contact dspence@ics.mq.edu.au
Tunable Ultraviolet Continuous-wave Laser Sources
Dr David Spence, A/Prof David Coutts
The goal of this project is to investigate the use of mode-locked lasers for pumping continuous wave (CW) lasers. The project will focus on the laser material Ce:LiCAF that is widely tunable in the ultraviolet spectral region. Experiments using this short lifetime material as well as using Ti:Sapphire crystals that have a far longer lifetime will carried out, and interpreted using numerical modeling. The noise characteristics, frequency tuning and laser threshold properties will be studied, and compared to experiments that use a CW pump source. Spectroscopic applications of the CW ultraviolet source will be investigated.
Contact dspence@ics.mq.edu.au
Guided Wave Polymer Optics
A/Prof Graham Town, A/Prof Karu Esselle
The aim of this project is to develop novel and inexpensive guided-wave polymer optical devices (e.g. optical fibres and integrated-optical devices) by clever microstructuring of novel nanocomposite materials (i.e. with tailored optical properties, including gain) for applications in optical sensing, switching, and telecommunications. Polymer devices have the advantage of being relatively bio-friendly, are relatively inexpensive to process, and are more readily modified to achieve specific optical properties than materials such as silica. The project will support continuing ARC and DEST funded work in the areas of microstructured (or "holey") optical fibres and materials development with collaborators in the UK and Australia.
Contact gtown@ics.mq.edu.au
Applications of Multiwavelength Fibre Lasers
A/Prof Graham Town, Dr Ken Grant, DSTO
Multiwavelength fibre lasers are of interest for their narrow linewidth and compact construction. Simultaneous lasing of several single longitudinal modes in a fibre laser was recently demonstrated by Macquarie University researchers (Pradhan et al, Opt. Lett 31(20) 2961 (2006)). Such lasers have significant advantages in sensing systems, e.g. in signal-to-noise-ratio and selectivity. The aim of this project is to develop applications of the latter laser, e.g. in distance measurement, spectroscopy, and microwave photonics (e.g. wireless distribution technology).
Contact gtown@ics.mq.edu.au
Polymer Fibre Sensors
A/Prof Graham Town, A/Prof Karu Esselle
A novel type of microstructured polymer fibre has recently been demonstrated at Macquarie University (R.M. Chaplin, G.E. Town, M.J. Withford, D. Baer, Proc. Integrated Photonics Research and Applications Topical Meeting (IPRA) and Nanophotonics Topical Meeting, Uncasville, May 24-28, NFC4, 2006). The aim of this project is to develop applications for this and other microstructured polymer fibres as sensing devices, particularly for in-vivo biomedical sensing. In such applications microstructured polymer fibres have some significant advantages over alternative technologies, e.g. the voids in holey fibres may be filled with fluid or used to pump small quantities of fluid into/out of the region of interest, polymer fibres have a much larger breaking strain than silica fibres, and polymer is significantly more "bio-friendly" than glass fibres. This project will investigate how these advantages may be exploited in biomedical and/or environmental sensing applications.
Contact gtown@ics.mq.edu.au
Laser Direct Writing of Photonic Devices: Investigation of laser-induced modification of glass
A/Prof Michael Withford, Dr Alex Fuerbach
Laser direct write micro-fabrication, where an ultrafast laser is focussed to a small, intense spot, and translated under computer control with respect to a target sample, can be used to modify the internal properties of bulk glass substrates and write "optical wires" (or waveguides) and discrete components such as amplifiers and filters. To date it is unclear what role the thermal history of the glass host has on this process. The project will undertake detailed studies investigating the influence between this aspect and the quality of photonic devices inscribed in key photonic glasses.
Contact withford@ics.mq.edu.au
Ultrafast Laser Direct Writing of Multiwavelength Waveguide Lasers
A/Prof Michael Withford, Dr Graham Marshall
Our group has developed a state of the art femtosecond laser-direct write processing facility that enables the fabrication of both waveguides and reflective structures (gratings) inside a range of passive and active glasses. This project will investigate both fibre and planar (written with the aforementioned facility) waveguide amplifiers, and develop processing strategies for integrating gratings within waveguide amplifiers. The end goal will be the realization of single and multi-wavelength waveguide lasers for defense and biophotonic applications.
Contact withford@ics.mq.edu.au
Background-free optical imaging of tag-free macromolecules
A/Prof Andrei Zvyagin
In most cases in optics, imaging resolution is limited to roughly the wavelength of light. At the same time, the optical detection sensitivity of individual particles is theoretically unlimited. Its practical achievement is limited by the signal-to-noise ratio, where the signal represents a number of detected photons from the particle, and noise comes from unwanted photons, termed background. Therefore, the progress in individual particle imaging relies on efficiency of the background suppression. In 80-s, the efficient image processing algorithm was introduced resulting in dramatic improvement of image quality, which permitted biologists to study cellular process in vivo with great amount of details. For example, filamentous cellular structures, microtubules, sized 25-nm in diameter, were routinely imaged. In recent times, imaging of individual 2.5-nm gold particles has been reported pushing detection sensitivity to such a level that optical detection of macromolecules, e.g. individual proteins, may become a reality. Click here for more details.
Contact azvyagin@ics.mq.edu.au
Application of multiphoton microscopy to study of collagen regeneration
A/Prof Andrei Zvyagin
Multiphoton microscopy (MPM) is an emerging imaging modality, which enables in vivo imaging of biological matter on the subcellular level. The key subsystem of MPM is a (very short pulsewidth) femto-second laser whose radiation is tightly focussed in a biological specimen, so that optical intensity becomes enormous for a short time of the pulse duration. This elicits non-linear optical response from the biological matter in the form of fluorescence or second-harmonic generation. In either case, the specimen now responds to the optical excitation. By rastering the focal spot across the specimen, an en face image of exquisite quality is acquired. This mechanism of MPM image formation entails the most valuable property of MPM, "optical sectioning", i.e. clearing a micron-thin image slice from the turbidity of the rest of the specimen. Click here for more details.
Contact azvyagin@ics.mq.edu.au
Application of luminescent nanodiamonds to intracellular imaging
A/Prof Andrei Zvyagin
Imaging at the molecular level has recently become a reality, if specific molecular sites are tagged with "optical labels". In this case scenario, even individual molecules become visible in the cell. These optical labels can be engineered as fluorophores, e.g. fluorescent dyes or quantum dots. Unfortunately, photoinstability and toxicity of these labels limit the scope of optical imaging, especially in the context of tracking individual molecules in the cell. Click here for more details.
Contact azvyagin@ics.mq.edu.au