ORCID Profile
0000-0003-0989-3813
Current Organisation
University of South Australia
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Optical Physics | Nanobiotechnology | Optical Physics not elsewhere classified |
Expanding Knowledge in the Physical Sciences | Expanding Knowledge in the Biological Sciences | Expanding Knowledge in Technology
Publisher: AIP Publishing
Date: 16-10-2006
DOI: 10.1063/1.2364058
Abstract: Quantum well intermixing was studied on InP∕InGaAs∕InGaAsP heterostructures under stress induced by a TiOx surface stressor. Results provide a comparison of thermal emission wavelength shift and effective emission wavelength shift for s les intermixed with and without applied stress. It is shown that TiOx decreases the measured thermal shift depending on the litude of the induced stress. It is also shown that the diffusion of point defects created during ion implantation prior to TiOx stressor deposition is significantly enhanced. This results in an increase of the effective wavelength shift by up to 300%.
Publisher: AIP Publishing
Date: 19-01-2009
DOI: 10.1063/1.3059573
Abstract: Whispering gallery modes (WGMs) are generated in fluorescent polymer microparticles in phosphate buffered saline (PBS) above the threshold for stimulated emission and compared to their characteristics below threshold. The WGM microresonators show an eightfold improvement of their signal-to-noise ratio and a threefold increase in their quality factor when operated above threshold. In an investigation on the benefits for biochemical sensing, a real-time adsorption kinetics of bovine serum albumin in PBS is monitored and compared with those kinetics acquired by means of a WGM microresonator operated below threshold as well as by surface plasmon resonance (SPR).
Publisher: SPIE
Date: 09-12-2016
DOI: 10.1117/12.2242705
Publisher: MDPI AG
Date: 31-08-2009
DOI: 10.3390/S90906836
Publisher: Elsevier BV
Date: 03-2011
DOI: 10.1016/J.BIOS.2010.12.018
Abstract: Sensors based on surface plasmon resonance (SPR) allow rapid, label-free, highly sensitive detection, and indeed this phenomenon underpins the only label-free optical biosensing technology that is available commercially. In these sensors, the existence of surface plasmons is inferred indirectly from absorption features that correspond to the coupling of light into a thin metallic film. Although SPR is not intrinsically a radiative process, when the metallic coating which support the plasmonic wave exhibits a significant surface roughness, the surface plasmon can itself couple to the local photon states, and emit light. Here we show that using silver coated optical fibres, this novel SPR transducing mechanism offers significant advantages compare to traditional reflectance based measurements such as lower dependency on the metallic thickness and higher signal to noise ratio. Furthermore, we show that more complex sensor architectures with multiple sensing regions scattered along a single optical fibre enable multiplexed detection and dynamic self referencing of the sensing signal. Moreover, this alternative approach allows to combine two different sensing technologies, SPR and fluorescence sensing within the same device, which has never been demonstrated previously. As a preliminary proof of concept of potential application, this approach has been used to demonstrate the detection of the seasonal influenza A virus.
Publisher: American Vacuum Society
Date: 05-2006
DOI: 10.1116/1.2172925
Abstract: Measurements of stress induced by TiOx layers on single quantum well InP based heterostructure are presented. Strain characterization has been performed by photoluminescence (PL) and micro-Raman spectroscopy. We present a comparison of the stress induced by TiOx and SiO2 layers which are commonly used as masking material for the quantum well intermixing process. Micro-Raman spectroscopy and PL revealed that TiO2 is creating a stress field in the top layers of the heterostructure, with a dependence on temperature and stressor thickness. A hysteresis phenomenon of the Raman shift has also been observed after measurements at low temperature (below 300 K) which shows that the stress created by TiOx exceeds the elastic limit of InP. On the other hand, there is no evidence that SiO2 is inducing stress. Rapid thermal annealing of s les covered with titanium oxide results in improvement of the thermal stability.
Publisher: SPIE
Date: 05-03-2015
DOI: 10.1117/12.2076943
Publisher: SPIE
Date: 24-11-2016
DOI: 10.1117/12.2242707
Publisher: MDPI AG
Date: 09-01-2015
DOI: 10.3390/S150101168
Publisher: SPIE
Date: 05-03-2013
DOI: 10.1117/12.2003522
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 05-2019
Publisher: SPIE
Date: 03-03-2015
DOI: 10.1117/12.2078526
Publisher: The Optical Society
Date: 27-10-2015
DOI: 10.1364/OE.23.028896
Publisher: The Optical Society
Date: 05-12-2016
Publisher: MDPI AG
Date: 14-03-2018
DOI: 10.3390/S18030857
Publisher: SPIE
Date: 15-05-2011
DOI: 10.1117/12.885066
Publisher: MDPI AG
Date: 22-06-2010
DOI: 10.3390/S100606257
Publisher: IEEE
Date: 07-2012
Publisher: The Optical Society
Date: 18-09-2013
DOI: 10.1364/OE.21.022566
Publisher: MDPI AG
Date: 29-09-2015
DOI: 10.3390/S151025090
Publisher: AIP Publishing
Date: 19-01-2015
DOI: 10.1063/1.4905931
Abstract: Whispering gallery mode lasers are of interest for a wide range of applications and especially biological sensing, exploiting the dependence of the resonance wavelengths on the surrounding refractive index. Upon lasing, the Q factors of the resonances are greatly improved, enabling measurements of wavelength shifts with increased accuracy. A way forward to improve the performance of the refractive index sensing mechanism is to reduce the size of the optical resonator, as the refractive index sensitivity is inversely proportional to the resonator dimensions. However, as the lasing threshold is believed to depend on the Q factor among other parameters, and the reduction of the microresonator size results in lower Q, this poses additional challenges for reaching the lasing threshold. In this letter, we demonstrate lasing in 10 μm diameter dye doped polystyrene microspheres in aqueous solution, the smallest polystyrene microsphere lasers ever reported in these conditions. We also investigate the dependence of the lasing threshold on the Q factor by changing the refractive index surrounding the sphere, highlighting a much stronger dependency than initially reported.
Publisher: The Optical Society
Date: 29-01-2015
DOI: 10.1364/OE.23.002577
Publisher: Wiley
Date: 21-07-2015
DOI: 10.1111/IJAG.12128
Publisher: Elsevier BV
Date: 12-2010
Publisher: MDPI AG
Date: 07-09-2018
DOI: 10.3390/S18092987
Abstract: Whispering gallery mode (WGM) resonators have become increasingly erse in terms of both architecture and applications, especially as refractometric sensors, allowing for unprecedented levels of sensitivity. However, like every refractometric sensor, a single WGM resonator cannot distinguish temperature variations from changes in the refractive index of the surrounding environment. Here, we investigate how breaking the symmetry of an otherwise perfect fluorescent microsphere, by covering half of the resonator with a high-refractive-index (RI) glue, might enable discrimination of changes in temperature from variations in the surrounding refractive index. This novel approach takes advantage of the difference of optical pathway experienced by WGMs circulating in different equatorial planes of a single microsphere resonator, which induces mode-splitting. We investigated the influence of the surrounding RI of the microsphere on mode-splitting through an evaluation of the sphere’s WGM spectrum and quality factor (Q-factor). Our results reveal that the magnitude of the mode-splitting increases as the refractive index contrast between the high-refractive-index (RI) glue and the surrounding environment increases, and that when they are equal no mode-splitting can be seen. Investigating the refractive index sensitivity of the in idual sub modes resulting from the mode-splitting unveils a new methodology for RI sensing, and enables discrimination between surrounding refractive index changes and temperature changes, although it comes at the cost of an overall reduced refractive index sensitivity.
Publisher: SPIE
Date: 20-02-2014
DOI: 10.1117/12.2039336
Publisher: SPIE
Date: 03-03-2014
DOI: 10.1117/12.2040788
Publisher: American Chemical Society (ACS)
Date: 08-03-2016
DOI: 10.1021/ACS.ANALCHEM.6B00365
Abstract: Biosensing within complex biological s les requires a sensor that can compensate for fluctuations in the signal due to changing environmental conditions and nonspecific binding events. To achieve this, we developed a novel self-referenced biosensor consisting of two almost identically sized dye-doped polystyrene microspheres placed on adjacent holes at the tip of a microstructured optical fiber (MOF). Here self-referenced biosensing is demonstrated with the detection of Neutravidin in undiluted, immunoglobulin-deprived human serum s les. The MOF allows remote excitation and collection of the whispering gallery modes (WGMs) of the microspheres while also providing a robust and easy to manipulate dip-sensing platform. By taking advantage of surface functionalization techniques, one microsphere acts as a dynamic reference, compensating for nonspecific binding events and changes in the environment (such as refractive index and temperature), while the other microsphere is functionalized to detect a specific interaction. The almost identical size allows the two spheres to have virtually identical refractive index sensitivity and surface area, while still having discernible WGM spectra. This ensures their responses to nonspecific binding and environmental changes are almost identical, whereby any specific changes, such as binding events, can be monitored via the relative movement between the two sets of WGM peaks.
Publisher: SPIE-Intl Soc Optical Eng
Date: 11-05-2015
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 06-2015
Publisher: SPIE
Date: 28-02-2014
DOI: 10.1117/12.2039328
Publisher: The Optical Society
Date: 28-05-2015
DOI: 10.1364/OE.23.014784
Publisher: SPIE
Date: 07-02-2008
DOI: 10.1117/12.762664
Publisher: SPIE
Date: 13-05-2011
DOI: 10.1117/12.883835
Publisher: The Optical Society
Date: 31-05-2016
DOI: 10.1364/OE.24.012466
Publisher: SPIE
Date: 05-10-2009
DOI: 10.1117/12.835283
Publisher: MDPI AG
Date: 23-12-2016
DOI: 10.3390/S17010012
Publisher: The Optical Society
Date: 17-10-2016
DOI: 10.1364/OE.24.024959
Publisher: SPIE
Date: 03-03-2015
DOI: 10.1117/12.2076889
Publisher: American Physical Society (APS)
Date: 12-11-2018
Publisher: SPIE
Date: 03-03-2014
DOI: 10.1117/12.2039589
Publisher: SPIE
Date: 07-2015
DOI: 10.1117/12.2186140
Publisher: Wiley
Date: 03-2017
Publisher: SPIE
Date: 11-10-2013
DOI: 10.1117/12.2038007
Publisher: SPIE
Date: 11-10-2013
DOI: 10.1117/12.2037511
Publisher: The Optical Society
Date: 10-04-2015
DOI: 10.1364/OE.23.009924
Publisher: SPIE
Date: 13-05-2011
DOI: 10.1117/12.883825
Publisher: The Optical Society
Date: 19-06-2015
DOI: 10.1364/OE.23.017067
Publisher: AIP Publishing
Date: 07-04-2008
DOI: 10.1063/1.2907491
Abstract: A new concept for an optical biosensor based on whispering gallery mode (WGM) excitations in clusters of spherical microresonators is presented. Clusters of microresonators offer the advantage to exhibit specific WGM spectra that can be considered as their fingerprint. Therefore, in idual clusters can be traced throughout an experiment even without knowledge of their precise positions. Polyelectrolyte adsorption onto clusters of 10μm polystyrene spheres is monitored in situ. It is shown that the WGMs shift to the same amount as those of a single microresonator and thus sensitivity does not depend on the number of microresonators present in the cluster.
Publisher: Springer Science and Business Media LLC
Date: 12-05-2016
DOI: 10.1557/ADV.2016.342
Publisher: OSA
Date: 2018
Publisher: SPIE
Date: 09-02-2012
DOI: 10.1117/12.909681
Publisher: Springer Science and Business Media LLC
Date: 22-10-2010
Publisher: SPIE
Date: 06-03-2013
DOI: 10.1117/12.2003612
Publisher: The Optical Society
Date: 27-05-2016
DOI: 10.1364/OME.6.002128
Publisher: SPIE
Date: 09-02-2012
DOI: 10.1117/12.907789
Publisher: American Chemical Society (ACS)
Date: 29-05-2015
Abstract: We demonstrate that exposure of nanocrystalline BaFCl:Sm(3+) X-ray storage phosphor to blue laser pulses with peak power densities on the order of 10 GW/cm(2) results in conversion of Sm(3+) to Sm(2+). This photoreduction is found to be strongly power-dependent with an initial fast rate, followed by a slower rate. The photoreduction appears to be orders of magnitude more efficient than that for previously reported systems, and it is estimated that up to 50% of the samarium ions can be photoreduced to the alent state. The main mechanism is most likely based on multiphoton electron-hole creation, followed by subsequent trapping of the electrons in the conduction band at the Sm(3+) centers. Nanocrystalline BaFCl:Sm(3+) is an efficient photoluminescent X-ray storage phosphor with possible applications as dosimetry probes, and the present study shows for the first time that the power levels of the blue light have to be kept relatively low to avoid the generation of Sm(2+) in the readout process. A system comprising the BaFCl:Sm(3+) nanocrystallites embedded into a glass is also envisioned for 3D memory applications.
Publisher: AIP Publishing
Date: 03-10-2011
DOI: 10.1063/1.3648109
Abstract: A technique for the excitation of whispering gallery modes (WGMs) has been demonstrated using a dye-doped microsphere positioned onto the tip of a suspended core microstructured optical fiber. With this configuration, we have shown that both the excitation and collection efficiency of the WGMs modulated fluorescence spectra of the dye are greatly improved compared to a more conventional excitation scheme an overall efficiency increase by a factor of 200 is demonstrated. It is also shown that positioning the resonator onto the fiber tip does not impact its sensitivity, providing a compact and robust architecture for applications such as localized in-vivo/vitro biosensing.
Publisher: SPIE
Date: 09-12-2016
DOI: 10.1117/12.2242259
Publisher: The Optical Society
Date: 09-05-2014
DOI: 10.1364/OE.22.011995
Publisher: SPIE
Date: 07-02-2008
DOI: 10.1117/12.762727
Publisher: Elsevier BV
Date: 07-2013
Publisher: Springer International Publishing
Date: 29-12-2015
Publisher: SPIE
Date: 22-02-2013
DOI: 10.1117/12.2004157
Publisher: Elsevier BV
Date: 10-2009
DOI: 10.1016/J.BIOS.2009.07.021
Abstract: Direct measurement of the biomechanical stress induced by a live cell during endocytosis is reported. Fluorescent dye-doped polystyrene microspheres were used as microscopic remote optical sensors applying whispering gallery modes (WGMs) as transducer mechanism. Monitoring of the WGMs throughout the incorporation of the microsphere into the cell enabled the determination of the deformation experienced by the microsphere, characterized by both a broadening and a blue shift of the resonances, and consequently the stress induced by the cell. The results reveal an unexpectedly high stress with a magnitude of up to five times that of the passive cortical tension, which can be only explained by a so far undetermined active stress component induced by the cytoskeletal machinery during particle incorporation. The method is adaptable to the study of any other kind of phagocyte and thus provides a novel research tool of high interest for cell biology.
Publisher: The Optical Society
Date: 03-05-2013
DOI: 10.1364/OE.21.011492
Location: France
Start Date: 07-2013
End Date: 07-2019
Amount: $2,965,000.00
Funder: Australian Research Council
View Funded Activity