photonics, materials and laser processing
Au fractal layers showing iridescence at various points
Interdisciplinary and multidisciplinary research is clearly driving entire fields these days so being prepared to face challenging and diverse frontiers to make genuine contributions in science and engineering is without a doubt as exciting as it gets. Projects in the areas described here can be tailored to suit your interests.
Self-assembled photonics (with Crossley, Rutledge, Gibson, Kristensen et al.)
(i) Self-assembly of nanoparticles
A new approach combining the so-called coffee-stain effect with stress induced refined fracturing has enable a new route to fabricating photonic waveguides and slabs from nanoparticles. A detailed characterisation of the self-assembly of nanoparticles will be investigated to explore the role of various parameters. Mixed nanoparticle sizes and types will be used to see how lattice configurations are altered. Of particular interest is the controlled adjustment of pore size and shape within self-assembled wires and slabs. There are a number of project directions possible including the development of metal contaminants, organic species and so on.
(ii) Self-assembly of porphyrins
We were one of the first groups to propose the concept of organic photonics and demonstrate using dipole bent porphyrins, self-assembly of iridescent organic wires and transparent slabs. This area has enormous scope for exploring both the physics and applications of these designer structures and will aim to demonstrate working waveguide devices.
(iii) Snap "frozen" biological species
The room temperature self-assembly technique has allowed the integration of various species ranging from laser dyes (e.g. Rhodamine 6G) to hemeproteins (e.g. cytochrome) directly into silica. In contrast to free-space degradation, the silica host appears to slow down charge transfer processes extending the lifetime of the species. This is analogous to solid-sate dye lasers using dye infiltrated glasses. The application to biodiagnostics and possibly drug delivery tremendous and this project will explore the integration and preservation of a range of species.
(iv) Optical wire magnetic composites
Magnetic composites are extremely important for a number of areas of research including Faraday rotators and metamaterials. This project will explore the new techniques in self-assembly to develop and characterise materials made up to silica and magnetic nanoparticles and other species with an aim to demonstrate a simple new approach to fabricating metamaterials.
(v) Single photon sources
Recent work has shown the integration of nitrogen-vacancy (NV) nanodiamonds into silica is possible using nanoparticle self-assembly. Single photon emitting centres were successfully embedded. This project will move to the next phase of developing practical single photon emitting source for potential quantum computing and sensing applications.
(vi) Nanoparticle self-assembly inside structured optical fibres
This project will examine a new field: the optimisation of novel core structures inside optical fibres to enhance functionality and allow new devices, lasers and sensors to be fabricated.
Plasmonics (with James Beattie et al.)
This project will explore the use of surface plasmon resonances (SPR) in metal and special oxide films to excite various species on the film and in solvents by changing the charge distribution with some solvents. Such resonances are increasingly popular since they potentially offer a low cost approach to improving the detection sensitivity of chemical and biological sensors. Laser processing will enable surface patterning of the SPR resonance sites so that localised fields can couple across to each other. A number of sensor configurations will be explored.
Extreme silica photonics (with Cook, UNSW, India, Germany, and Brazil)
Understanding glass and the role of hydrogen within has led to fibre Bragg gratings that survive beyond 1100°C. The optical fibre acts as a superb miniature processing laboratory that can help provide fundamental information on glass transformations particularly within complex glassy systems. This project explores using dopants in the glass in further optimising the performance and applying the techniques to two dimensions. In collaboration with the new fibre facility at UNSW the role of frozen-in stresses in enhancing the magnitude and stability of change will be explored.
Optically interrogated chemical sensors & fibre laboratories
Chemical sensing, especially in the energy and environmental sectors, is one of the fastest growing research fields in photonics. The silica fibre host is perhaps the most desirable technology platform for a number of reasons including the ability to perform safe and remote interrogation and to have multi-functionality. Various project opportunities to develop novel sensors in fibre and integrated form are available. In particular, laser processing of surfaces is an extremely important project to both understand and control robust attachment of molecules to surfaces.
For further information, please contact:
interdisciplinary Photonics Laboratories (iPL)
School of Chemistry
Madsen Building, F09
University of Sydney NSW 2006
Phone: +61 2 9351 1934