Photonics PhD Projects

Photonics PhD Projects

PhD Projects on Offer in the Department of Physics and Astronomy at Macquarie University focused on Photonic and Optical Science


The projects below are available for possible PhD projects. We encourage you to read them, follow the hyperlinks to read background information on the science related to the projects, and email the Chief Project scientist (bold font), for more information. If you are interested to apply to do a PhD on a particular project please submit your Expression of Interest application by the next deadline by clicking HERE.

Application of Pulsed Vacuum-Ultraviolet Photon Sources to Surface Science of Glass and Medical Polymers

Carman - Applications of Pulsed

Dr. Robert Carman - Macquarie University

Prof. Deb Kane - Macquarie University

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.

Diamond Photonics 

Mildren - Diamond Photonics

A/Prof. Rich Mildren - Macquarie University

A/Prof David Spence
Dr Robert Williams
Dr James Downes

MQ Photonics Research Centre, Macquarie University

Diamond’s highly symmetric lattice and strong bonding brings forth a host of extreme physical properties, many of which we only beginning to discover. The Diamond Laser Group has a large program to explore the nonlinear optical properties of diamond bulk and surfaces which are fundamental to a range of photonic, quantum and nanodevice technologies. These efforts have already led to a number of major scientific advances, some of which have been patented and have substantial potential for leading to new products.

We have projects seeking enthusiastic PhD students in areas of on-chip diamond lasers, quantum random generators, and 3D “printing” of diamond. You will become part of the effort seeking to make the breakthroughs that bring about real world-changing impact.

For more details about the host group and research centre click here:

[1] A. Lehmann, C. Bradac, and R. P. Mildren, Nature Commun. vol. 5, 3341 (2014)
[2] R.P. Mildren, Intrinsic optical properties of diamond in Optical Engineering of Diamond (Wiley) pp1-34, (2013)
[3] R.J. Williams, J. Nold, M. Strecker, O. Kitzler, A. McKay, T. Schreiber, and R.P. Mildren, Laser Photon. Rev., vol. 9, no. 4, pp. 405–411, (2015).

Nano- and Atom-scale Structuring of Diamond using 2-photon Induced Carbon Ejection

Rich Mildren - Diamond Carbon Ejection

A/Prof. Rich Mildren - Macquarie University

Dr. James Downes - Macquarie University

Optical techniques for processing materials with a resolution less than the wavelength of light have advanced significantly in recent years. However, despite the highly selective nature of light-matter interactions, efforts to increase resolution towards the atomic scale are hampered by diffusion of the absorbed energy into the surrounding matrix. We have recently shown that diamond surfaces exhibit the remarkable capability to be patterned using ultraviolet lasers with ultra-precise depth and lateral resolution (Nature Commun. 2013). Furthermore, the detailed shape of structures depends sensitively on the polarization with respect to lattice bond directions. This PhD project is aimed to further understand the mechanism underpinning the atom removal process and to exploit the technique to demonstrate a range of novel diamond processing capabilities. These include fabrication of nano-scale optical elements, precision atomic-layer removal for surface electronics and complex 3D micro-structures made of diamond. It is aimed to develop techniques for solving current challenges in fabrication of diamond devices for future applications spanning a range of disciplines. The project will provide excellent experience in a broad range of scientific skills spanning optics, surface physics and nano-engineering.

Nonlinear Dynamics of Semiconductor Lasers

Prof. Deb Kane - Macquarie University

A range of projects topics are available in experimental nonlinear laser dynamics and related theory and data analysis. Currently, the group is leading a number of national and international research collaborations, in addition to advancing our own experimental program. The latter is primarily focussed on the diverse dynamics of a range of nonlinear laser systems. The diversity within a single system and from different systems lend the systems to broad ranging applications in communications and imaging. Increasingly it is the analysis and understanding of the complexity of the systems that is transferable to other areas of science such as climate change, physiology and finance. External funding support for the area is currently provided by a SIEF Round 4 project grant joint between NICTA, Sirca, Macquarie University and Sydney University. This project will be at the forefront of laser nonlinear dynamics research, internationally. The project will develop experimental, theoretical and collaborative research skills.

Laser Supported Techniques for Conservation in Art and Cultural Heritage

Kane - Laser Conservation of Artwork

Prof. Deb Kane - Macquarie University

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. Pigment de-adhesion is a particularly serious issue for traditional Aboriginal bark paintings. The project will involve collaboration with conservation scientist and conservators in Museums and Art Galleries. All the studies will be completed as quantitative science and can be presented internationally as laser-materials interactions research. Publications in high quality journals will result. New laser processing solutions will be an outcome. The project will develop experimental, theoretical and collaborative research skills.

Photonics of Certain Spider Orb Webs

Prof. Deb Kane - Macquarie University

Dr. Alex Fuerbach - Macquarie University

Opportunities exist for students to complete research on the photonics and optics of certain spider orb webs. Considering orb webs, constructed in bright environments, as an optical as well as a mechanical device is informing new hypotheses on their function. The optical materials of this subset of webs are highly birefringent, highly dispersive, have high optical nonlinearity and represent a natural, self assembled protein. As an optical material it is nanocomposite in form and an excellent source for biomimetic innovation ideas. Projects can range from theoretical simulation of optical elements from the webs, researching new micro-optical techniques to measure the optical properties, through to micro- and nano-scale microscopy with an emphasis on understanding the physics of the microscopy techniques in interpreting physical characteristics from microscopy images. The project will develop experimental, theoretical and collaborative research skills.

Optical Surface Profiling for Measuring Nano-objects and Devices

Prof. Deb Kane - Macquarie University

Dr. Doug Little - Macquarie University

We have demonstrated that optical surface profiling instruments – based on phase shifting interference microscopy can be used to measure key size parameters of nano-objects – such as the diameter of nanowires. Further high impact research will extend this technique to measuring refractive index of nano-objects in addition to pushing the technique to its limits. It is predicted we should be able to measure size parameters of nano-objects as small as a few nanometres. Additionally, new optical surface profiling experimental techniques for application to active optoelectronic devices will be researched. Through transmissive media capability of the state-of-the-art NT9800 optical surface profiler facility will be utilised. The type of measurements that are planned have never been undertaken before anywhere in the world. The student will build broad experimental capability with sophisticated experimental techniques and develop theoretical understanding of the physics underpinning the project in order to perform thorough and high level analysis and interpretation of project data. This project will suit a student looking for an opportunity to develop broad and multiple research capabilities.

Building New Device Capabilities for Continuous-wave Intracavity Raman Lasers

Prof. Helen Pask - Macquarie University

A/Prof. David Spence - Macquarie University

Diode pumped crystalline Raman lasers offer a practical and efficient approach to generating laser output at wavelengths that are not easily accessible by conventional laser sources. Raman lasers are unique in a number of ways and the physics involved gives rise to interesting and unusual effects, such as wavelength-selectable operation. A PhD project is available to investigate Continuous-wave Intracavity Raman lasers operating in the visible and near infrared. Of particular interest is power scaling to levels above 10 Watts, efficiency scaling of high and low power systems, device miniaturisation and single longitudinal mode operation. These goals will be pursued through a combination of experimental and numerical modelling studies. This project will suit a motivated student interested in optical physics, resonator design, non-linear optics, and the development of laser sources that can be applied to real world problems.

Precision Raman lasers

A/Prof. David Spence - Macquarie University

A/Prof. Rich Mildren - Macquarie University

We are collaborating with a UK company M Squared Lasers to use diamond Raman lasers to create tunable high-power single mode sources. Building on the M Squared Lasers flagship ‘SolsTiS’ product, one of the world’s most controlled and versatile lasers, we will develop resonantly enhanced Raman lasers to generate a spectrum spanning single mode laser source for applications in atom trapping and atomic clocks.

Developing the ‘Ti:Sapphire of the UV’: New femtosecond laser sources in the deep ultraviolet

A/Prof. David Spence - Macquarie University

Prof. David Coutts - Macquarie University

Ultrafast ‘femtosecond’ lasers are work-horses of optical science. They are used as ‘strobes’ to freeze fast action on unprecedentedly short timescales. They can be used to drive high-power physics experiments, such as ionizing plasmas, and can be used to machine metals and glasses. The ubiquitous femtosecond laser is the Ti:Sapphire laser; it operates only in the infra-red spectral region, and experimenters can find this limiting their studies.

We are developing the world’s first femtosecond laser source operating in the ultraviolet. Based on a crystal doped with cerium, these lasers have the potential to directly generate pulses as short as 3 femtoseconds at 290 nm, and there is the potential to further shorten the output to achieve attosecond pulses. This is an exciting project, applying the knowledge and experience gained with the industry-standard Ti:Sapphire lasers to this new laser material that has been dubbed ‘the Ti:Sapphire of the UV’.

Laser Direct Writing of Photonic Devices: Investigation of laser-induced modification of glass

Prof. Michael Withford - Macquarie University 

Dr Alex Fuerbach - Macquarie University

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, as part of a large collaboration with our partners in a Marie Curie International Research Exchange Scheme: University Paris-Sud, Friedrich Schiller University and University of Southampton.

Ultrafast Laser Direct Writing of Novel Waveguide Lasers

Prof. Michael Withford - Macquarie University

Dr Peter Dekker - Macquarie University
A/Prof Mike Steel - Macquarie University

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 defence and biophotonic applications. Our collaborators include the University of Adelaide.

Making Light and Sound Work Together in Nanoscale Optical Chips

Prof. Michael Steel - Macquarie University

These days we tend to think of communication by sound as primitive compared to the wonders of optical communication. In fact, “optoacoustics”, or the study of light-sound interactions, is one of the hottest topics in integrated nonlinear optics. While photons tend to be protected from the environment, mechanical sound waves or “phonons” interact strongly with the environment and can couple back to light waves making an interface between optics and the wider world. Phonons also underpin Stimulated Brillouin Scattering, the strongest of all optical nonlinearities. By harnessing these interactions in compact semiconductor chips, we will obtain completely new opportunities for sensing, ultra high-speed electronics and new ultra-narrow laser sources. We can even exploit sound-light connections at the fully quantum level to create new states of light.

The fundamental theoretical obstacle is that light and sound waves often refuse to coexist in the same waveguide: structures that confine light are leaky for sound and vice versa. This theoretical project will build new mathematical formalisms at the boundary of quantum and classical nonlinear optics to solve the mutual confinement problem of sound and light, and truly open up optoacoustic nonlinearities. From this starting point, we will exploit the interplay of crystal structure and optical dispersion to enable new approaches to optical frequency conversion and control of quantum entanglement. The impact of topological and nonreciprocal propagation effects adds further theoretical richness. The work will involve both analytic and numerical work and interact closely with a world-leading experimental program.

For more information refer to the research webpage.

Smart Design and Optimisation of 3D optical Waveguides for Astronomy and Quantum Science

Prof. Michael Steel - Macquarie University

Prof. Michael Withford - Macquarie University

Direct writing of optical waveguides with femtosecond lasers has brought about a new generation of unique three-dimensional (3D) optical devices with applications in astronomy, quantum physics and optical communications. Our group is a world leader in the design and application of such structures. The enormous freedom of 3D structures, with literally hundreds or thousands of design parameters, means that conventional approaches to design cannot adequately identify the most efficient or effective structures.

This project will develop innovative numerical techniques using ideas from convex optimisation theory to enable a completely new level of capability for laser-written 3D waveguide devices. Depending on the interests of the student, the project could be purely theoretical, working in partnership with experimental students, or could be partly experimental addressing the entire process from design to fabrication and physical characterisation. Similarly, the student can determine whether they wish to target advances in quantum devices, optical processing or astronomy. The project will use advanced computational facilities including supercomputers and GPU techniques and exploit our 250m2 laboratory suite of state of the art optical fabrication and test equipment.

For more information please refer to the research webpage.

Extreme Nonlinear Optics in a Tiny Piece of Glass

Prof. Michael Steel - Macquarie University

Prof. Michael Withford - Macquarie University
Dr Luke Helt - Macquarie University

One of the most exciting developments in recent photonics is the rise of direct-write optical waveguides: channels for guiding and processing light written directly in chips of glass by powerful femtosecond lasers. The 3D geometry allows waveguides to twist around each other in complex patterns, allowing numerous applications in quantum optics, communications and astronomy. However, while understanding of linear devices is quite mature, the potential for nonlinear effects in direct-write waveguides has barely been explored.

In this project, we will model, design, fabricate and test a new class of highly nonlinear waveguides written into exotic strongly nonlinear glasses. We will explore the use wavefront engineering to design the nonlinear response at will and engineer the transverse mode structure to control the interplay of nonlinearity and dispersion. The devices will be applied to frontier problems in quantum information, frequency conversion and ultra-broadband light sources.

For more information please refer to the research webpage.

High-Q Mechanical Resonators

Prof. Jason Twamley - Macquarie University

Dr. James Downes - Macquarie University

The field of optomechanics – where one studies the interaction of light forces with mechanical moving objects has recently enjoyed a huge surge of interest. Much of the reason for this interest comes from the desire to explore new physical systems where novel physical effects appear but also to build exquisitely precise sensors for magnetic/electric etc fields. To reach exciting new regions of physics and possible high precision sensing one seeks to develop mechanical motional oscillators which possess as little damping as possible i.e. with high motional Q-uality factors. One way to achieve this is via mechanical resonators which have no mechanical contact with their surroundings e.g. are levitated/trapped in space. The typical method to achieve this is via optical tweezers but such trapping comes with some difficulties relating to laser noise possibly heating the motion of the mechanical oscillator. In this project we will develop passive trapping of particles in ultra-high-vacuum. These particles will be stably trapped and oscillate in space. The goal of this project will be towards achieving ultra-high motional Quality factors and high motional frequencies for these trapped mechanical oscillators and to determine the feasibility to use such oscillators for sensitive metrology. The project will be primarily experimental in nature but will also require some theory/numerics to develop/fit the theory to the experiment.

Extension scope:
This project probes an exciting new area of meso/nanoscopic control – mechanical trapped systems. This new field of research has a wealth of novel phenomena to be explored, understood and utilised for a variety of purposes eg. ultra-sensitive sensing. It is expected that there are extensions of this project to multiple PhD projects also with the potential for national/international collaborations.

Ultrafast Mid-infrared Fiber Laser Systems

Dr. Alex Fuerbach  - Macquarie University

A/Prof. Stuart Jackson - Macquarie University

The development of light sources that emit at mid-IR wavelengths is currently a highly active and significant research field as this spectral region not only coincides with the vibrational- rotational absorption lines of many molecules but also contains several atmospheric transmission windows.

The vast majority of gaseous chemical substances exhibit fundamental vibrational absorption bands in the mid-infrared, i.e. in a wavelength region that extends from about 2 μm to about 10 μm. The absorption of light by these fundamental bands provides a nearly universal means for the detection of specific substances and is exploited in trace gas spectroscopy and molecular fingerprinting, respectively. Over recent years, mid-infrared spectroscopy has also been identified as a promising tool for early cancer diagnostics as it can provide a wealth of both biochemical and morphological information that has the potential to identify markers associated with pre-malignant and carcinogenic change.

However, despite the obvious significance and importance that those applications hold, the actual development and practical implementation is progressing at a snail’s pace because progress is held back by a lack of available light sources. Thus, it is believed that fiber lasers based on rare- earth doped heavy metal fluoride glasses (ZBLAN) will play a crucial role for the generation of mid-IR radiation in the future [1].

In this project, we will develop novel mode-locked all-fibre laser systems with unprecedented performance and robustness. The key element that will enable the development of the proposed mid-IR fiber systems will be a novel type of fiber Bragg grating (FBG). Very recently we have introduced a novel continuous core-scanning technique that will enable the direct inscription of FBGs into optical fibers using femtosecond laser pulses [2]. Not only are those gratings reflective elements with tailored reflection bandwidth, we will also be able to precisely control the dispersion characteristics of those structures which will allow us to implement advanced dispersion management techniques in an all-fibre setup without the necessity to include any additional bulk optical components.

For more details about the host group and research centre click here: CUDOS@MQ

[1] S.D. Jackson: “Towards high-power mid-infrared emission from a fibre laser”, Nat. Photonics 6, 423 (2012).
[2] S. Antipov, M. Ams, R. Williams, E. Magi, M.J. Withford, A. Fuerbach: "Direct infrared femtosecond laser inscription of chirped fiber Bragg gratings", Optics Express 24, 30 (2016).

3-D Integrated Photonic Devices for Mode-locked all-fiber Lasers

Dr. Alex Fuerbach  - Macquarie University

A/Prof. Stuart Jackson - Macquarie University
Dr. Simon Gross - Macquarie University
Dr. Darren Hudson
The University of Sydney

This project is aimed at the design and the fabrication of 3-D integrated devices for mode-locked all-fiber lasers using the femtosecond laser direct-write method [1].

The idea is to create a saturable-loss mechanism that is based on nonlinear mode coupling in an index-matched waveguide array [2]. To date, one important obstacle to the construction of a monolithic all-fiber mode locked laser is the incorporation of a mode-locker, i.e. a fast saturable absorber, into the laser cavity. In the past, the coupling of light into a saturable absorber in a fibre laser geometry has involved the introduction of optical elements such as microscope objectives to focus the intracavity beam and thus to obtain the high intensities needed to achieve saturation. However, these optical elements increase the complexity, size, and weight of the laser system and because of reflections and absorption also introduce unwanted instabilities. Moreover, these elements also raise the pump power threshold for mode locking. We thus plan to develop of a new mode-locking technique that is designed to improve the robustness, efficiency and reliability of fibre laser systems, involving an array of nonlinearly-coupled waveguides. The device will be fabricated using our in-house state-of-the-art femtosecond laser direct-write facility and will directly be integrated into a mid-infrared fluoride-glass fibre laser [3].

For more details about the host group and research centre click here: CUDOS@MQ

[1] R.R. Gattass, E. Mazur: “Femtosecond laser micromachining in transparent materials”, Nat. Photonics 2, 219 (2008)”
[2] D.D. Hudson, K. Shish, T.R. Schibli, J.N. Kutz, D.N. Christodoulides, R. Morandotti, S.T. Cundiff: “Nonlinear femtosecond pulse reshaping in waveguide arrays”, Opt. Letters 33, 1440 (2008).
[3] S.D. Jackson: “Towards high-power mid-infrared emission from a fibre laser”, Nat. Photonics 6, 423 (2012).

Cellular organization during transport and signalling

Dr. Varun K. A. Sreenivasan - Macquarie University

Dr. Senthil Arumugam - University of New South Wales

Through a collaboration between researchers at Macquarie University and the University of New South Wales, the project aims to understand the l pathways in signalling and transport in cellular systems. Towards this goal, we aim at:

1. Developing novel nanotechnology tools, including nanoparticle engineering for state-of-the-art microscopy techniques [1].
2. Developing and implementing state-of-the-art optical microscopy techniques (Lattice light sheet microscopy, single molecule techniques) for studying cellular processes [2, 3].
3. Developing innovative image analysis solutions for cell biology.

For more details about the host group and research centre click here and here.

[1] Nano-ruby: a promising fluorescent probe for background-free cellular imaging, Andrew M Edmonds, Mushtaq A Sobhan, Varun KA Sreenivasan, Ekaterina A Grebenik, James R Rabeau, Ewa M Goldys, Andrei V Zvyagin, Particle & Particle Systems Characterization. (2013).
[2] Lattice light-sheet microscopy: Imaging molecules to embryos at high spatiotemporal resolution.
[3] Cytoskeletal pinning controls phase separation in multicomponent lipid membranes, Senthil Arumugam, Eugene P Petrov and Petra Schwille, Biophysical Journal. (2015).

Development of Cutting-edge THz applications

lee-dev_of_cutting_edge_thz_appsDr Andrew Lee - Macquarie University

Prof. Helen Pask - Macquarie University

Terahertz (THz) radiation has the potential to revolutionise applications in security, medicine and industry. It has been referred to as the “Final Frontier” of the electromagnetic spectrum because of the significant challenges associated with its generation and detection.  At Macquarie University we are developing the latest generation of THz lasers to spearhead Australia’s research efforts in this burgeoning field. These lasers have the potential to enable revolutionary, real-world applications for this type of radiation. This project will make use of these newly-developed THz laser sources to demonstrate their ability to significantly impact applications in biology and medicine.

The THz lasers developed at Macquarie University are compact, highly-efficient and frequency-tunable, making use of the non-linear stimulated polariton scattering [1] effect. The THz source architecture is similar to that of a solid-state Raman laser which itself is built upon cost-effective and proven diode-based pump sources and crystalline materials [2]. To date, our sources can generate over 10 μW of frequency tunable laser radiation from ~ 1 – 3.5 THz [3,4]. Specific applications which will be targeted in this project include measuring the hydration levels in plants [5], measuring moisture levels in biological tissues with an aim of cancer detection [6], and detection of illicit, concealed materials [7]. Here techniques such as THz spectroscopy and THz imaging will be employed.

In this project, the candidate will gain extensive experience in setting up experiments to facilitate such measurements, investigation of THz-materials interactions in order to interpret experimental data, and theoretical modelling of systems.

[1] Yarborough, J. M., et al. "Efficient, tunable optical emission from LiNbO3 without a resonator." Applied Physics Letters 15, 102 (1969).
[2] Piper, James A., and Helen M. Pask. "Crystalline Raman lasers." Selected Topics in Quantum Electronics, IEEE Journal of 13, 692 (2007).
[3] Lee, Albert, Yabai He, and Helen Pask. "Frequency-Tunable THz Source Based on Stimulated Polariton Scattering in." Quantum Electronics, IEEE Journal of 49, 357 (2013).
[4] Lee, Andrew J., and Helen M. Pask. "Continuous wave, frequency-tunable terahertz laser radiation generated via stimulated polariton scattering."Optics letters 39, 442 (2014).
[5] Gente, Ralf, and Martin Koch. "Monitoring leaf water content with THz and sub-THz waves." Plant methods 11, 1 (2015).
[6] Woodward, Ruth M., et al. "Terahertz pulse imaging in reflection geometry of human skin cancer and skin tissue." Physics in medicine and biology 47, 3853 (2002).
[7] Kawase, Kodo, et al. "Non-destructive terahertz imaging of illicit drugs using spectral fingerprints." Optics express 11, 2549 (2003).

Optical Vortices and Optical Cyclones


Prof. David Coutts - Macquarie University

Vortex beams are unusual in that they are optical beams which carry orbital angular momentum and are sometimes described as twisted light. Usually such beams or fibre modes have relatively low degree of vorticity (0<L<20). Recently we have shown how to generate beams with extremely high orbital angular momentum (L>1,000) in multimode optical fibres. We have shown how these beams can be converted to produce an optical cyclone consisting of a rotating, spiralled and twisted beam.

In this exciting project we will explore these highly unusual optical fields, including their generation, propagation characterisation and manipulation. We will also explore their first applications which can range from materials processing, to manipulation of particles to communications systems.

Nonlinear Random Lasers

Prof. Judith Dawes - Macquarie University

Random lasers, in which light experiences multiple scattering events to extend its path length in the gain medium, act as extended sources with partially coherent output. The emitted light can be useful for imaging and medical diagnostics and the lasers exhibit a range of interesting behaviours. Scattering arises due to imperfections in the laser material or added particles which scatter the light within the medium. We have previously demonstrated random lasers with dielectric or plasmonic scattering particles. The addition of nonlinear optical particles to the random laser offers intriguing possibilities to extend the wavelength of operation of the random lasers, for example towards the biologically important tissue transmission window in the infrared.

Here we aim to study the effect of nonlinear optical scattering particles on the behaviour of the random laser, characterise and model their behaviour under different operating regimes, and understand the mechanisms that affect the operation of these lasers.

jd001 jd002

Figure shows a liquid random laser and a solid film random laser: left, a cuvette of dye solution with scatterers and right, a polymer film with dye and scatterers, being pumped by a separate excitation laser.

Enhanced Graphene Photodetection

Prof. Judith Dawes - Macquarie University

Graphene is a material which is only 1 atom thick, and yet has measurable optical absorption across the full spectrum from optical to THz. When graphene is in contact with metallic electrodes, it becomes doped and can be biased so that it behaves as a semiconductor. Since light can excite surface plasmons in appropriate gold structures, we can increase the interaction of the graphene with incoming radiation via excitation of surface plasmons, and enhance photodetection using graphene. Having demonstrated this approach successfully, our aim is to improve the sensitivity of these detectors, and to extend the performance to a wide wavelength range from visible to infrared and THz.


Figure shows a schematic of a plasmonic enhanced graphene-gold photodetector.

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