ORCID Profile
0000-0003-4852-3735
Current Organisation
University of New South Wales
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Research Topics
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.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Analytical Chemistry | Functional Materials | Quantum Physics | Colloid and Surface Chemistry | Condensed Matter Physics | Sensor Technology (Chemical aspects) | Elemental Semiconductors | Surfaces and Structural Properties of Condensed Matter | Photonics, Optoelectronics and Optical Communications | Electronic and Magnetic Properties of Condensed Matter; Superconductivity | Nonlinear Optics and Spectroscopy | Quantum Physics not elsewhere classified |
ANZSRC Socio-Economic Objective (SEO)
Expanding Knowledge in the Physical Sciences | Medical Instruments | Expanding Knowledge in Engineering | Expanding Knowledge in the Biological Sciences | Expanding Knowledge in Technology
Related Links
Publications
<title>Photonic crystal slab made from porous silicon</title>
Publisher: SPIE
Date: 08-12-2004
DOI: 10.1117/12.608682
Colloidal silicon quantum dots: From preparation to the modification of self-assembled monolayers (SAMs) for bio-applications
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C3CS60353A
Abstract: Summarizes recent advances in the preparation, surface modification and bio-applications of silicon quantum dots.
Clear quantum-confined luminescence from crystalline silicon/SiO 2 single quantum wells
Publisher: AIP Publishing
Date: 23-03-2004
DOI: 10.1063/1.1691489
Abstract: Crystalline silicon single quantum wells (QWs) were fabricated by high-temperature thermal oxidation of ELTRAN® (Epitaxial Layer TRANsfer) silicon-on-insulator (SOI) wafers. The Si layer thicknesses enclosed by thermal SiO2 range from 0.8 to 5 nm. Luminescence energies from such QWs vary from 1.77 to 1.35 eV depending on the Si layer thickness, without evidence for interface-mediated transition seen in earlier work. The ability to detect quantum-confined luminescence seems to arise from the use of ELTRAN SOI wafers, from suppressed interface state luminescence by high-temperature oxidation and, possibly, from interface matching by crystalline silicon oxide.
Mesoporous silicon photonic crystal microparticles: Towards single-cell optical biosensors
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C005340F
Using Spectroscopic Techniques to Interrogate Trapping Dynamics of Nanoscale Objects
Publisher: OSA
Date: 2013
Porous silicon photonic crystals for detection of infections
Publisher: SPIE
Date: 10-10-2012
DOI: 10.1117/12.940757
Two-photon luminescence study of optically trapped InP semiconductor nanowires
Publisher: IEEE
Date: 08-2011
Experimental Observation of Modulation Instability and Optical Spatial Soliton Arrays in Soft Condensed Matter
Publisher: American Physical Society (APS)
Date: 18-05-2007
Broadband laser mirrors made from porous silicon
Publisher: AIP Publishing
Date: 20-04-2004
DOI: 10.1063/1.1739507
Abstract: We have designed, fabricated, and tested laser mirrors made entirely from porous silicon (PSi). PSi high reflectors and output couplers were designed for continuous-wave and mode-locked Ti:Sapphire lasers that were tuned between 730 nm and 940 nm. The mode-locked version of this laser produced 80 fs pulses at 85 MHz, parameters very similar to those observed with the commercial mirrors. We also made a PSi-dye laser by inserting a dye-filled cuvette between two PSi mirrors that was pumped from the side with a pulsed, frequency doubled, Nd:YAG laser. Lasers working with the PSi mirrors exhibited stable operation over time.
Nonconservative dynamics of optically trapped high-aspect-ratio nanowires
Publisher: American Physical Society (APS)
Date: 24-02-2016
Polaronic exciton binding energy in iodide and bromide organic-inorganic lead halide perovskites
Publisher: AIP Publishing
Date: 07-12-2015
DOI: 10.1063/1.4936418
Abstract: The last 4 years have seen the rapid emergence of a new solar cell technology based on organic-inorganic lead halide perovskites, primarily CH3NH3PbI3 and related halides involving Cl and Br. Debate continues on the role of excitons and free carriers in these materials. Recent studies report values of exciton binding energy for the iodide ranging from 0.7 meV to 200 meV, with vastly different implications for device operation and design. In the present work, previously neglected polarons are shown likely to have a major impact in determining excitonic properties. Polaronic exciton binding energies calculated using effective longitudinal optical phonon energies, deduced from permittivity measurements, are shown consistent with experimental energies for good quality s les of CH3NH3PbI3 and CH3NH3PbBr3, as determined over a large temperature range from optical absorption data. Bandgaps determined simultaneously show a discontinuity at the orthorhombic to tetragonal phase transition for the iodide, but not for the bromide.
Different functionalization of the internal and external surfaces in mesoporous materials for biosensing applications using click chemistry
Publisher: American Chemical Society (ACS)
Date: 09-12-2011
DOI: 10.1021/LA102599M
β-NaYF4 :Er3+ nanocrystal films as a spectral converter to improve photoconversion efficiency of crystalline silicon solar cells
Publisher: IEEE
Date: 06-2013
High quality optical components from porous silicon
Publisher: IEEE
Date: 2005
Phase transformations in CdSe quantum dots induced by reaction time
Publisher: Elsevier BV
Date: 02-2015
Up-conversion luminescence enhancement in erbium-doped porous silicon photonic crystals for photovoltaics
Publisher: SPIE
Date: 10-02-2011
DOI: 10.1117/12.872115
Fishnet metamaterials with incorporated titanium absorption layer
Publisher: IOP Publishing
Date: 19-11-2013
Fabrication and tuning of high quality porous silicon microcavities
Publisher: Wiley
Date: 05-2003
Thermoradiative Power Conversion from HgCdtTe Photodiodes and Their Current–Voltage Characteristics
Publisher: American Chemical Society (ACS)
Date: 09-05-2022
Optical bistability in mesoporous silicon microcavity resonators
Publisher: AIP Publishing
Date: 05-2011
DOI: 10.1063/1.3585782
Abstract: We report on the observation of significant optical bistability in the transmission and reflection properties of mesoporous silicon microcavities when illuminated with a 150 ns pulsed laser at 532 nm. The observed optical hysteresis is shown to be transient in nature and the properties are strongly dependent on the porosity of the cavity layer. The onset and damage threshold intensity are also shown to be porosity dependent. Our modeling suggests that the observed effects are due to changes in the nonlinear refractive index where the transient lifetime increases with increasing porosity. We investigate the role of surface states on influencing the bistable process by passivating the internal porous surface with hydrosilylation chemistry.
Green laser light (532nm) activates a chloride current in the C1 neuron of Helix aspersa
Publisher: Elsevier BV
Date: 03-2008
DOI: 10.1016/J.NEULET.2008.01.017
Abstract: Five hundred and thirty-two nanometers laser light evokes neuron-specific electrical responses in identified neurons of Helix ganglia. Such responses are intensity-dependent over the range 25-1500 mW, readily reversible and repeatable. Detailed experiments on the C1 neuron, which is inhibited by 532 nm light, showed that inhibition results from a selective increase in transmembrane Cl(-) ion conductance. Experiments with calcium-sensitive microelectrodes suggest that the response does not result from an increase in [Ca(2+)](i). The change in Cl(-) ion conductance probably occurs in the extensive plasmalemma infoldings of the proximal axon.
Optical vortex trap for resonant confinement of metal nanoparticles
Publisher: Optica Publishing Group
Date: 27-03-2008
DOI: 10.1364/OE.16.004991
Abstract: The confinement and controlled movement of metal nanoparticles and nanorods is an emergent area within optical micromanipulation. In this letter we experimentally realise a novel trapping geometry near the plasmon resonance using an annular light field possessing a helical phasefront that confines the nanoparticle to the vortex core (dark) region. We interpret our data with a theoretical framework based upon the Maxwell stress tensor formulation to elucidate the total forces upon nanometric particles near the particle plasmon resonance. Rotation of the particle due to orbital angular momentum transfer is observed. This geometry may have several advantages for advanced manipulation of metal nanoparticles.
Optimising porous silicon Bragg reflectors for narrow spectral resonances
Publisher: AIP Publishing
Date: 25-10-2018
DOI: 10.1063/1.5048618
Abstract: Achieving sharp spectral resonances in porous silicon based photonic structures is of significant practical importance for improving the accuracy of refractive index-based sensing in chemical and biochemical applications. Here, we show that by compensating for depth related heterogeneities in the etching conditions, we are able to reduce the porosity modulation in Bragg reflectors to below 1% and achieve absorption limited spectral widths of 7 nm in the visible part of the spectrum. Such narrowband Bragg reflectors provide markedly improved sensing capability for real-time monitoring of refractive index changes compared with reflectors with broader spectral features.
Parameter exploration of optically trapped liquid aerosols
Publisher: American Physical Society (APS)
Date: 17-11-2010
Quantum well intermixing for optoelectronic device integration
Publisher: IEEE
Date: 2002
Effect of Sb and As spray on emission characteristics of InAs quantum dots with AlAs capping layer
Publisher: IOP Publishing
Date: 12-09-2017
Influence of GaAsSb structural properties on the optical properties of InAs/GaAsSb quantum dots
Publisher: Elsevier BV
Date: 10-2017
Depth-resolved chemical modification of porous silicon by wavelength-tuned irradiation
Publisher: American Chemical Society (ACS)
Date: 22-10-2012
DOI: 10.1021/LA303649U
Abstract: The ability to impart discrete surface chemistry to the inside and outside of mesoporous silicon is of great importance for a range of biomedical applications, from selective (bio)sensing to tissue-specific drug delivery. Here we present a generic strategy toward achieving depth-resolved functionalization of the external and internal porous surfaces by a simple change in the wavelength of the light being used to promote surface chemical reactions. UV-assisted hydrosilylation, limited by the penetration depth of UV light, is used to decorate the outside of the mesoporous structure with carboxylic acid molecules, and white light illumination triggers the attachment of dialkyne molecules to the inner porous matrix.
Spatial selectivity of impurity free vacancy disordering using different dielectric layers for photonic/optoelectronic integrated circuits
Publisher: IEEE
Date: 2003
Dark field optical tweezers for studying nanoparticle dynamics
Publisher: IEEE
Date: 12-2012
Light emission from 1D silicon photonic crystals containing erbium
Publisher: SPIE
Date: 07-2004
DOI: 10.1117/12.525966
Incorporation of colloidal quantum dots into silicon photonic structures
Publisher: IEEE
Date: 02-2010
Optical microcavities with subnanometer linewidths based on porous silicon
Publisher: AIP Publishing
Date: 17-12-2002
DOI: 10.1063/1.1531226
Abstract: We have fabricated a number of high-quality porous silicon optical microcavities operating in the near infrared that exhibit cavity resonances with subnanometer linewidths. This was achieved through the low temperature anodic oxidation of highly doped p-type silicon wafers. We have investigated the optical properties of these microcavities using reflectivity and photoluminescence measurements and compared our results with theoretical predictions. From our analysis, we conclude that, for the low temperature fabrication process, the refractive index difference between adjacent layers of the multilayered structure is maximized while optical losses in the cavity are minimized. Furthermore, by considering the origin of optical losses in these microcavities, we demonstrate that fluctuations in the position of the resonance wavelength and optical absorption play an important role in the realization of high-quality interferometric structures.
Air-stable PbS quantum dots synthesized with slow reaction kinetics via a PbBr2 precursor
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5RA13499D
Abstract: High resolution of EDX image shows the bromine located on same position of PbS quantum dot.
The origin of gate hysteresis in p-type Si-doped AlGaAs/GaAs heterostructures
Publisher: IEEE
Date: 12-2012
Photoluminescence of antimony sprayed indium arsenide quantum dots for novel photovoltaic devices
Publisher: AIP Publishing
Date: 04-03-2013
DOI: 10.1063/1.4794018
Abstract: Emission from InAs/GaAs quantum dots (QDs) treated with Sb sprays of 7.5, 15, 22.5, and 30 s duration immediately prior to capping with GaAs has been studied via temperature dependent photoluminescence. Room temperature spectra show a significant increase in output intensity as the quantum dots are exposed to the Sb spray, but this improvement is lost when the Sb exposure is extended beyond 15 s. For the 7.5 s and 15 s Sb spray s les, temperature-dependent photoluminescence taken between 20 and 300 K show an increase in emission for increasing temperature from 30 to ∼100 K, for s les with an Sb spray before rolling off at temperatures in excess of 100 K, an effect ascribed to a small energy barrier close to the dots. Fitting of the temperature dependent data suggests that the impact of the energy barrier is only seen for the s les with lower defect densities in the immediate vicinity of the quantum dots. Results found when varying the excitation wavelength suggest the energy barrier is most likely located away from the top of the quantum dots, with it suggested that the inferred energy barrier may be due to Sb clustering around the base of the quantum dots in the capping layer, or incorporated Sb in the wetting layer of the QDs.
Vertical Integration of Cell-Laden Hydrogels with Bioinspired Photonic Crystal Membranes
Publisher: Wiley
Date: 29-10-2018
Differential Interference Contrast-Based Interrogation of Plasmonic Gold Nanohole Arrays for Label-Free Imaging Sensing
Publisher: American Chemical Society (ACS)
Date: 07-10-2021
Dielectric resonator: cavity-enhanced optical manipulation in the near field
Publisher: SPIE
Date: 31-08-2006
DOI: 10.1117/12.681988
Synthesis of type-II CdSe(S)/Fe2O3 core/shell quantum dots: the effect of shell on the properties of core/shell quantum dots
Publisher: Springer Science and Business Media LLC
Date: 22-02-2016
Effects of Zn Doping on Intermixing in InGaAs/AlGaAs Laser Diode Structures
Publisher: The Electrochemical Society
Date: 2003
DOI: 10.1149/1.1588304
3D optical trapping inside a hollow-core microstructured optical fiber
Publisher: OSA
Date: 2010
High-resolution light-activated electrochemistry on amorphous silicon-based photoelectrodes
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0CC02959A
Abstract: The spatial resolution of silicon photoelectrochemistry is improved to 500 nm by using amorphous silicon, 60 times improvement as compared to crystalline silicon.
Erratum: Elevated temperature anodized Nb 2 O 5 -A photoanode material with exceptionally large photoconversion efficiencies (ACS Nano (2012) 6 (4045-4053) DOI: 10.1021/nn300408p)
Publisher: American Chemical Society (ACS)
Date: 31-05-2012
DOI: 10.1021/NN302256G
All-silicon omnidirectional mirrors based on one-dimensional photonic crystals
Publisher: AIP Publishing
Date: 12-05-2003
DOI: 10.1063/1.1574403
Study of gamma irradiation effect on commercial TiO2 photocatalyst
Publisher: Elsevier BV
Date: 07-2014
DOI: 10.1016/J.APRADISO.2014.02.001
Abstract: The aim of this work is to understand the effect of gamma irradiation on commercial TiO2 photocatalyst for water treatment applications. Previous studies concluded that gamma-irradiation is able to modify the electronic properties of TiO2 based photocatalysts and consequently their photocatalytic performance. However, there are some discrepancies in the literature where on one hand a significant enhancement of the material properties is reported and on the other hand only a weak effect is observed. In this study a surface effect on TiO2 is confirmed by using low and medium gamma irradiation doses.
Using double chirping to minimise absorption in lossy broadband dielectric reflectors
Publisher: The Optical Society
Date: 11-06-2018
DOI: 10.1364/OME.8.001827
Optical tweezers-based characterisation of gold core–satellite plasmonic nano-assemblies incorporating thermo-responsive polymers
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/C9NR07891F
Abstract: We report on the characterisation of the optical properties and dynamic behaviour of optically trapped single stimuli-responsive plasmonic nanoscale assemblies.
Nonlinear Optical Processes in Optically Trapped InP Nanowires
Publisher: American Chemical Society (ACS)
Date: 07-09-2011
DOI: 10.1021/NL2020262
Abstract: We report on the observation of nonlinear optical excitation and related photoluminescence from single InP semiconductor nanowires held in suspension using a gradient force optical tweezers. Photoexcitation of free carriers is achieved through absorption of infrared (1.17 eV) photons from the trapping source via a combination of two- and three-photon processes. This was confirmed by power-dependent photoluminescence measurements. Marked differences in spectral features are noted between nonlinear optical excitation and direct excitation and are related to band-filling effects. Direct observation of second harmonic generation in trapped InP nanowires confirms the presence of nonlinear optical processes.
Functionalization of porous silicon based photonic crystals with organic monolayers
Publisher: IEEE
Date: 2005
Difference in hot carrier cooling rate between Langmuir-Blodgett and drop cast PbS QD films due to strong electron-phonon coupling
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7NR05247B
Abstract: The carrier dynamics of lead sulphide quantum dot (PbS QD) drop cast films and closely packed ordered Langmuir–Blodgett films are studied with ultra-fast femtosecond transient absorption spectroscopy.
Sensor-side Brownian noise reduction in optically trapped probe microscopy
Publisher: SPIE
Date: 07-09-2018
DOI: 10.1117/12.2320850
Photoluminescence study of optically trapped InP semiconductor nanowires
Publisher: IEEE
Date: 12-2010
Silicon Nanoparticles: Correlating Spectral Properties with Brownian Dynamics
Publisher: OSA
Date: 2017
Near-field optical manipulation with cavity enhanced evanescent fields
Publisher: SPIE
Date: 09-02-2006
DOI: 10.1117/12.660814
Sb dissociative surface coverage model for incorporation of antimony in GaAsSb layers grown on GaAs (0 0 1) substrates
Publisher: Elsevier BV
Date: 11-2019
Localized Surface Plasmon Resonance Spectroscopy Combined With Optical Tweezers For Nanorod Dynamics Characterization
Publisher: OSA
Date: 2015
Construction and calibration of an optical trap on a fluorescence optical microscope
Publisher: Springer Science and Business Media LLC
Date: 12-2007
Abstract: The application of optical traps has come to the fore in the last three decades. They provide a powerful, sterile and noninvasive tool for the manipulation of cells, single biological macromolecules, colloidal microparticles and nanoparticles. An optically trapped microsphere may act as a force transducer that is used to measure forces in the piconewton regime. By setting up a well-calibrated single-beam optical trap within a fluorescence microscope system, one can measure forces and collect fluorescence signals upon biological systems simultaneously. In this protocol, we aim to provide a clear exposition of the methodology of assembling and operating a single-beam gradient force trap (optical tweezers) on an inverted fluorescence microscope. A step-by-step guide is given for alignment and operation, with discussion of common pitfalls.
Redox-active monolayers in mesoporous silicon
Publisher: American Chemical Society (ACS)
Date: 20-07-2012
DOI: 10.1021/JP303980X
The effect of (NH4)(2)S-x passivation on the (311)A GaAs surface and its use in AlGaAs/GaAs heterostructure devices
Publisher: IOP Publishing
Date: 17-07-2013
DOI: 10.1088/0953-8984/25/32/325304
Abstract: We have studied the efficacy of (NH4)2Sx surface passivation on the (311)A GaAs surface. We report XPS studies of simultaneously-grown (311)A and (100) heterostructures showing that the (NH4)2Sx solution removes surface oxide and sulfidizes both surfaces. Passivation is often characterized using photoluminescence measurements we show that while (NH4)2Sx treatment gives a 40-60 × increase in photoluminescence intensity for the (100) surface, an increase of only 2-3 × is obtained for the (311)A surface. A corresponding lack of reproducible improvement in the gate hysteresis of (311)A heterostructure transistor devices made with the passivation treatment performed immediately prior to gate deposition is also found. We discuss possible reasons why sulfur passivation is ineffective for (311)A GaAs, and propose alternative strategies for passivation of this surface.
Near-field optical micromanipulation with cavity enhanced evanescent waves
Publisher: AIP Publishing
Date: 29-05-2006
DOI: 10.1063/1.2208272
Abstract: We show that the forces associated with near-field optical micromanipulation can be greatly increased through the use of cavity enhanced evanescent waves. This approach utilizes a resonant dielectric waveguide structure and a prism coupler to produce Fabry-Pérot-like cavity modes at a dielectric-fluid interface. Fabricated structures show a ten times enhancement in the optical interaction and optical force for micrometer-sized colloids. In addition, stable accumulation and ordering of large scale arrays of colloids are demonstrated using two counter-propagating cavity enhanced evanescent waves.
Porous silicon based narrow line-width rugate filters
Publisher: Elsevier BV
Date: 02-2007
Slow-light-enhanced upconversion for photovoltaic applications in one-dimensional photonic crystals
Publisher: The Optical Society
Date: 05-10-2011
DOI: 10.1364/OL.36.003990
TiO2films prepared by ultrasonic spray pyrolysis
Publisher: Informa UK Limited
Date: 04-2010
One-pot synthesis of colloidal silicon quantum dots and surface functionalization via thiol-ene click chemistry
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2CC35954E
Abstract: A solution method for preparing surface functionalized colloidal silicon quantum dots (SiQDs) is presented. SiQDs prepared by this method are reasonably monodispersed and can be further functionalized via thiol-ene click reactions to introduce specific functionalities (i.e. -NH(2), -COOH, -SO(3)(-), alkane, alkene).
Ultrasensitive and Specific Measurement of Protease Activity Using Functionalized Photonic Crystals
Publisher: American Chemical Society (ACS)
Date: 08-09-2015
DOI: 10.1021/ACS.ANALCHEM.5B02529
Abstract: Herein is presented a microsensor technology as a diagnostic tool for detecting specific matrix metalloproteinases (MMPs) at very low concentrations. MMP-2 and MMP-9 are detected using label free porous silicon (PSi) photonic crystals that have been made selective for a given MMP by filling the nanopores with synthetic polymeric substrates containing a peptide sequence for that MMP. Proteolytic cleavage of the peptide sequence results in a shift in wavelength of the main peak in the reflectivity spectrum of the PSi device, which is dependent on the amount of MMP present. The ability to detect picogram amounts of MMP-2 and MMP-9 released by primary retinal pigment epithelial (RPE) cells and iris pigment epithelial (IPE) cells stimulated with lipopolysaccharide (LPS) is demonstrated. It was found that both cell types secrete higher amounts of MMP-2 than MMP-9 in their stimulated state, with RPE cells producing higher amounts of MMPs than IPE cells. The microsensor performance was compared to conventional protease detection systems, including gelatin zymography and enzyme linked immunosorbent assay (ELISA). It was found that the PSi microsensors were more sensitive than gelatin zymography PSi microsensors detected the presence of both MMP-2 and MMP-9 while zymography could only detect MMP-2. The MMP-2 and MMP-9 quantification correlated well with the ELISA. This new method of detecting protease activity shows superior performance to conventional protease assays and has the potential for translation to high-throughput multiplexed analysis.
Biomedical Optics Express feature issue introduction: optical trapping applications (OTA)
Publisher: The Optical Society
Date: 05-10-2015
DOI: 10.1364/BOE.6.004273
Study of intermixing in InGaAs∕(Al)GaAs quantum well and quantum dot structures for optoelectronic∕photonic integration
Publisher: Institution of Engineering and Technology (IET)
Date: 2005
Porous silicon based rugate filters
Publisher: IEEE
Date: 2005
Elevated Temperature Anodized Nb2O5: A Photoanode Material with Exceptionally Large Photoconversion Efficiencies
Publisher: American Chemical Society (ACS)
Date: 24-04-2012
DOI: 10.1021/NN300408P
Abstract: Here, we demonstrate that niobium pentoxide (Nb(2)O(5)) is an ideal candidate for increasing the efficiencies of dye-sensitized solar cells (DSSCs). The key lies in developing a Nb(2)O(5) crisscross nanoporous network, using our unique elevated temperature anodization process. For the same thicknesses of ∼4 μm, the DSSC based on the Nb(2)O(5) layer has a significantly higher efficiency (∼4.1%) when compared to that which incorporates a titanium dioxide nanotubular layer (∼2.7%). This is the highest efficiency among all of the reported photoanodes for such a thickness when utilizing back-side illumination. We ascribe this to a combination of reduced electron scattering, greater surface area, wider band gap, and higher conduction band edge, as well as longer effective electron lifetimes.
Combined optical trapping and microphotoluminescence of single InP nanowires
Publisher: AIP Publishing
Date: 07-09-2009
DOI: 10.1063/1.3225148
Abstract: In this letter, we demonstrate that microphotoluminescence may be combined with optical trapping for effective optical characterization of single target InP semiconductor nanowires in suspension. Using this technique, we may investigate structural properties of optically trapped nanowires, such as crystalline polytypes and stacking faults. This arrangement may also be used to resolve structural variations along the axis of the trapped nanowire. These results show that photoluminescence measurements may be coupled with optical tweezers without degrading the performance of the optical trap and provide a powerful interrogation tool for preselection of components for nanowire photonic devices.
Characterization of Semiconductor Nanowires Using Optical Tweezers
Publisher: American Chemical Society (ACS)
Date: 02-05-2011
DOI: 10.1021/NL200720M
Abstract: We report on the optical trapping characteristics of InP nanowires with dimensions of 30 (±6) nm in diameter and 2-15 μm in length. We describe a method for calibrating the absolute position of in idual nanowires relative to the trapping center using synchronous high-speed position sensing and acousto-optic beam switching. Through brownian dynamics we investigate effects of the laser power and polarization on trap stability, as well as length dependence and the effect of simultaneous trapping multiple nanowires.
Interdiffusion in InGaAs quantum dots by ion implantation
Publisher: IEEE
Date: 2002
Resolving Stable Axial Trapping Points of Nanowires in an Optical Tweezers Using Photoluminescence Mapping
Publisher: American Chemical Society (ACS)
Date: 14-02-2013
DOI: 10.1021/NL304607V
Abstract: Axially resolved microphotoluminescence mapping of semiconductor nanowires held in an optical tweezers reveals important new experimental information regarding equilibrium trapping points and trapping stability of high aspect ratio nanostructures. In this study, holographic optical tweezers are used to scan trapped InP nanowires along the beam direction with respect to a fixed excitation source and the luminescent properties are recorded. It is observed that nanowires with lengths on the range of 3-15 μm are stably trapped near the tip of the wire with the long segment positioned below the focus in an inverted trapping configuration. Through the use of trap multiplexing we investigate the possibility of improving the axial stability of the trapped nanowires. Our results have important implication for applications of optically assisted nanowire assembly and optical tweezers based scanning probes microscopy.
Suppression of interdiffusion in In/sub 0.5/Ga/sub 0.5/As/GaAs quantum dots
Publisher: IEEE
Date: 2002
Measurement of Hydrodynamic Coupling by Time-shared Optical Tweezers
Publisher: OSA
Date: 2015
Decoupling the effects of confinement and passivation on semiconductor quantum dots
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6CP03438A
Abstract: Plasma synthesised Si QDs are deposited in liquids to decouple confinement and passivation effects on their optical properties.
Single charge regime electrodynamic force measuring in solution by upconversion photonic force microscope
Publisher: Research Square Platform LLC
Date: 14-10-2022
DOI: 10.21203/RS.3.RS-2160647/V1
Abstract: Precise force measurement is critical to probing biological events and physics processes, spanning from molecular motor’s motion to the Casimir effect 1 and the detection of gravitational wave 2 . Yet, despite extensive technology developments, the 3D nanoscale measurement of weak forces in aqueous solutions poses a significant challenge. Techniques that rely on the optically trapped nanoprobe are beset with difficulties, including low light scattering for force measuring and high localization error from their Brownian motion. Here, we report the measurement of the long-distance electrodynamic force on single nanocrystals suspended in aqueous solution with only 11 net charges. To achieve this, we develop an upconversion photonic force microscope that encompasses a diffraction-limited tracking-based force sensing theory and the advance of lanthanide ion resonance force probe 3,4 . The tracking method is based on neural network empowered super-resolution localization, where the position of force probe is extracted from the optical astigmatism modified point spread functon(PSF), enabling the measurement of trap stiffness for nanoparticles through equipartition theorem with a force sensitivity down to 592.9 attoNewtons (aN), that is, 5 times lower than the reported best sensitivity value 5 . We further demonstrate that the technology can measure a single nanocrystal's electrophoresis force and zeta potential, experimentally verifying Loeb's empirical relationship. This work offers new opportunities for detecting single-charge dynamics over long-distance and sub-cellular single molecular level biomechanical force.
Optical hysteresis in mesoporous silicon microcavities
Publisher: IEEE
Date: 12-2010
Wavelength selective filter based on polarization control in a photonic bandgap structure with a defect
Publisher: The Optical Society
Date: 12-2011
DOI: 10.1364/OE.19.025643
Mapping optical process in semiconductor nanowires using dynamic optical tweezers
Publisher: SPIE
Date: 09-10-2012
DOI: 10.1117/12.928558
Porous Silicon Omnidirectional Bragg Reflector for Si Solar Cells
Publisher: OSA
Date: 2014
Using light scattering to resolve Brownian rotation dynamics of optically trapped Au nanorods
Publisher: AIP Publishing
Date: 02-2018
DOI: 10.1063/1.5018334
Abstract: Optically trapped Au nanorods are known to adopt a preferential orientation when trapped in three dimensions at the focus of linearly polarised optical tweezers. Trapped nanorods experience both translational and rotational perturbations due to Brownian motion that are governed by the strength of the trap and associated shape-dependent hydrodynamic properties. In this study, we make use of the strong angular dependent light scattering of the localised surface plasmon resonances to interrogate the rotational dynamics of trapped nanorods principally aligned along the propagation axis of the trapping laser. Our measurements reveal that significant rotational dynamics can be observed whilst maintaining stable translational trapping at low powers.
Semiconductor Nanostructures towards Electronic and Optoelectronic Device Applications
Publisher: Wiley
Date: 02-2014
Comparison of interdiffusion between single and stacked-layer InGaAs/GaAs quantum dots
Publisher: IEEE
Date: 2003
Optical tweezers beyond refractive index mismatch using highly doped upconversion nanoparticles
Publisher: Springer Science and Business Media LLC
Date: 18-02-2021
DOI: 10.1038/S41565-021-00852-0
Abstract: Optical tweezers are widely used in materials assembly
Hydrothermal synthesis of highly luminescent blue-emitting ZnSe(S) quantum dots exhibiting low toxicity
Publisher: Elsevier BV
Date: 07-2016
DOI: 10.1016/J.MSEC.2016.03.061
Abstract: Highly luminescent quantum dots (QDs) that emit in the visible spectrum are of interest to a number of imaging technologies, not least that of biological s les. One issue that hinders the application of luminescent markers in biology is the potential toxicity of the fluorophore. Here we show that hydrothermally synthesized ZnSe(S) QDs have low cytotoxicity to both human colorectal carcinoma cells (HCT-116) and human skin fibroblast cells (WS1). The QDs exhibited a high degree of crystallinity, with a strong blue photoluminescence at up to 29% quantum yield relative to 4',6-diamidino-2-phenylindole (DAPI) without post-synthetic UV-irradiation. Confocal microscopy images obtained of HCT-116 cells after incubation with the QDs highlighted the stability of the particles in cell media. Cytotoxicity studies showed that both HCT-116 and WS1 cells retain 100% viability after treatment with the QDs at concentrations up to 0.5g/L, which makes them of potential use in biological imaging applications.
Impact of metal crystallinity-related morphologies on the sensing performance of plasmonic nanohole arrays
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0NR00619J
Abstract: Low surface roughness and large metal grain sizes improve the sensitivity of a plasmonic nanohole array sensor.
Photoluminescence in crystalline silicon quantum wells
Publisher: AIP Publishing
Date: 15-01-2007
DOI: 10.1063/1.2430919
Abstract: Crystalline silicon single quantum wells (QWs) with a minimum Si layer thickness of around 1nm were fabricated by high temperature thermal oxidation of separation by implantation of oxygen (SIMOX) and epitaxial layer transfer (ELTRAN®) silicon-on-insulator (SOI) wafers. Not only Si thickness but also defect-free SOI materials may be important factors for observation of quantum-confined transition in the Si QWs. Si QWs fabricated from SIMOX SOI wafers showed strong interface-mediated luminescence, which is independent of Si thickness, at 1.63 and 1.49eV in the Si thickness range from 1to7nm. On the other hand, Si QWs fabricated from ELTRAN SOI wafers showed very strong thickness dependent luminescence in the range of 1.36–1.77eV without interface-mediated luminescence, where the Si thickness range was 3–1nm. The ability to detect quantum-confined luminescence seems to arise from the use of high-quality defect-free ELTRAN SOI wafers, from suppressed interface state luminescence by high temperature oxidation, and, possibly, from interface matching by crystalline silicon oxide. Hydrogen passivation suggests luminescence from a weak SiO state at around 1.59eV, but luminescence due to quantum confinement is more predominant in the ELTRAN Si QWs.
Electrochemical Fabrication of Silicon-Based Micro-Nano-Hybrid Porous Arrays for Hybrid-Lattice Photonic Crystal
Publisher: The Electrochemical Society
Date: 2017
DOI: 10.1149/2.0361712JSS
Near-Field Optical Micromanipulation
Publisher: Elsevier
Date: 2008
A multimodal optical and electrochemical device for monitoring surface reactions: Redox active surfaces in porous silicon Rugate filters
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2CP43461J
Abstract: Herein, mesoporous silicon (PSi) is configured as a single sensing device that has dual readouts as a photonic crystal sensor in a Rugate filter configuration, and as a high surface area porous electrode. The as-prepared PSi is chemically modified to provide it with stability in aqueous media and to allow for the subsequent coupling of chemical species, such as via Cu(I)-catalyzed cycloaddition reactions between 1-alkynes and azides ("click" reactions). The utility of the bimodal capabilities of the PSi sensor for monitoring surface coupling procedures is demonstrated by the covalent coupling of a ferrocene derivative, as well as by demonstrating ligand-exchange reactions (LER) at the PSi surface. Both types of reactions were monitored through optical reflectivity measurements, as well as electrochemically via the oxidation/reduction of the surface tethered redox species.
PL mapping and optimized optical trapping of nanowires SLM beam shaping
Publisher: IEEE
Date: 12-2012
Surface plasmon enhanced light emission from AlN/GaN superlattices structure in the UV region
Publisher: IEEE
Date: 12-2014
Manipulating the Quantum Coherence of Optically Trapped Nanodiamonds
Publisher: American Chemical Society (ACS)
Date: 10-2018
Photolithographic strategy for patterning preformed, chemically modified, porous silicon photonic crystal using click chemistry
Publisher: American Chemical Society (ACS)
Date: 03-07-2013
DOI: 10.1021/AM4006012
Abstract: Porous silicon (PSi) is an ideal platform for label-free biosensing, and the development of porous silicon patterning will open a pathway to the development of highly parallel PSi biochips for detecting multiple analytes. The optical response of PSi photonic crystal is determined by the changes in the effective bulk refractive index resulting from reactions/events occurring within the internal pore space. Therefore, introducing precise chemical functionalities in the pores of PSi is essential to ensure device selectivity. Here we describe the fabrication of PSi patterns that possess discrete chemical functionalities that are restricted to precise locations. The key difference to previous patterning protocols for PSi is that the entire porous material is first modified with a self-assembled monolayer of a α,ω-diyne adsorbate prior to patterning using a microfabricated titanium mask. The distal alkyne moieties in the monolayer are then amenable to further selective modification by the archetypal "click" reaction, the copper catalyzed alkyne-azide cycloaddition (CuAAC), using the titanium mask as a resist. This type of patterning is suitable for further immobilization of biological recognition elements, and presents a new platform for highly parallel PSi biosensor for multiple detections.
Deposition of CdSe quantum dots on graphene sheets
Publisher: Elsevier BV
Date: 02-2014
Functionalised porous silicon as a biosensor: Emphasis on monitoring cells in vivo and in vitro
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3AN00081H
Abstract: Porous silicon photonics is the ideal platform for high sensitivity, high selectivity monitoring of biological molecules in a complex fluidic environment. The potential of this technology was identified almost 15 years ago, however, it has taken considerable advances in porous silicon surface chemistry, photonics, and micro-fabrication to create truly effective devices that can provide new insights into the behaviour of biological systems. In this review we provide a critical assessment of the development of porous silicon optical biosensors from the early demonstrations of affinity based sensing to the current trends in monitoring single cell activity and perspectives in the use of photonic microparticles for biomedical applications.
Antibody modified porous silicon microparticles for the selective capture of cells
Publisher: American Chemical Society (ACS)
Date: 10-06-2014
DOI: 10.1021/BC500144U
Abstract: Herein, the ability of porous silicon (PSi) particles for selectively binding to specific cells is investigated. PSi microparticles with a high reflectance band in the reflectivity profile are fabricated, and subsequently passivated and modified with antibodies via the Cu(I)-catalyzed alkyne-azide cycloaddition reaction and succimidyl activation. To demonstrate the ability of the antibody-modified PSi particles to selectively bind to one cell type over others, HeLa cells were transfected with surface epitopes fused to fluorescent proteins. The antibody-functionalized PSi particles showed good selectivity for the corresponding surface protein on HeLa cells, with no significant cross-reactivity. The results are important for the application of PSi particles in cell sensing and drug delivery.
Roadmap for optical tweezers
Publisher: IOP Publishing
Date: 04-2023
Abstract: Optical tweezers are tools made of light that enable contactless pushing, trapping, and manipulation of objects, ranging from atoms to space light sails. Since the pioneering work by Arthur Ashkin in the 1970s, optical tweezers have evolved into sophisticated instruments and have been employed in a broad range of applications in the life sciences, physics, and engineering. These include accurate force and torque measurement at the femtonewton level, microrheology of complex fluids, single micro- and nano-particle spectroscopy, single-cell analysis, and statistical-physics experiments. This roadmap provides insights into current investigations involving optical forces and optical tweezers from their theoretical foundations to designs and setups. It also offers perspectives for applications to a wide range of research fields, from biophysics to space exploration.
Porous silicon: a versatile optical material
Publisher: SPIE
Date: 25-03-2004
DOI: 10.1117/12.524715
Femtosecond Multidimensional Spectroscopy to Study Carrier Dynamics of Photonic Materials
Publisher: IEEE
Date: 2005
“Designing high-performance nighttime thermoradiative systems for harvesting energy from outer space” by Zhang et al.: comment
Publisher: Optica Publishing Group
Date: 06-10-2021
DOI: 10.1364/OL.426514
Abstract: The current–voltage characteristics presented by Zhang et al. in their recent work [ Opt. Lett. 45 , 5929 ( 2020 10.1364/OL.400349 ) ] on designing thermoradiative systems overestimate the achievable power using the proposed material by several orders of magnitude.
Optical micromanipulation takes hold
Publisher: Elsevier BV
Date: 02-2006
Enhancing Quantum Dots for Bioimaging using Advanced Surface Chemistry and Advanced Optical Microscopy: Application to Silicon Quantum Dots (SiQDs)
Publisher: Wiley
Date: 31-08-2015
Abstract: Fluorescence lifetime imaging microscopy is successfully demonstrated in both one- and two-photon cases with surface modified, nanocrystalline silicon quantum dots in the context of bioimaging. The technique is further demonstrated in combination with Förster resonance energy transfer studies where the color of the nanoparticles is tuned by using organic dye acceptors directly conjugated onto the nanoparticle surface.
Optical properties of erbium-implanted porous silicon microcavities
Publisher: AIP Publishing
Date: 18-10-2004
DOI: 10.1063/1.1808235
Abstract: We have used ion implantation for erbium doping of mesoporous silicon microcavities. Optically active erbium-doped microcavities with Q factors in excess of 1500 have been demonstrated. We observed strong modification of the emission properties of the erbium in the microcavity with an accompanying cavity enhancement factor of 25. In addition, power- and temperature-dependent photoluminescence measurements indicate that erbium-implanted porous silicon has excitation mechanism very similar to that of erbium in a crystalline silicon host.
Infrared induced photo-dynamics of NV centres in optically trapped nanodiamond
Publisher: SPIE
Date: 07-09-2018
DOI: 10.1117/12.2320821
Optical deflection and sorting of microparticles in a near-field optical geometry
Publisher: Optica Publishing Group
Date: 06-03-2008
DOI: 10.1364/OE.16.003712
Abstract: Near-field optical micromanipulation permits new possibilities for controlled motion of trapped objects. In this work, we report an original geometry for optically deflecting and sorting micro-objects employing a total internal reflection microscope system. A small beam of laser light is delivered off-axis through a total internal reflection objective which creates an elongated evanescent illumination of light at a glass/water interface. Asymmetrical gradient and scattering forces from this light field are seen to deflect and sort polystyrene microparticles within a fluid flow. The speed of the deflected objects is dependent upon their intrinsic properties. We present a finite element method to calculate the optical forces for the evanescent waves. The numerical simulations are in good qualitative agreement with the experimental observations and elucidate features of the particle trajectory. In the size range of 1 microm to 5 microm in diameter, polystyrene spheres were found to be guided on average 2.9 +/- 0.7 faster than silica spheres. The velocity increased by 3.0 +/- 0.5 microms(-1) per microm increase in diameter for polystyrene spheres and 0.7 +/- 0.2 microms(-1) per microm for silica. We employ this size dependence for performing passive optical sorting within a microfluidic chip and is demonstrated in the accompanying video.
Optical transitions from SiO/sub 2//crystalline Si/SiO/sub 2/ quantum wells
Publisher: IEEE
Date: 2002
Extending omnidirectional reflection bands in one-dimensional photonic crystals
Publisher: IOP Publishing
Date: 02-05-2018
Substrate independent assembly of optical structures guided by biomolecular interactions
Publisher: American Chemical Society (ACS)
Date: 05-11-2010
DOI: 10.1021/AM1007084
Abstract: The chip-scale integration of optical components is crucial for technologies as erse as optical communications, optoelectronics displays, and photovoltaics. However, the realization of integrated optical devices from discrete components is often h ered by the lack of a universal substrate for achieving monolithic integration and by incompatibilities between materials. Emergent technologies such as chip-scale biophotonics, organic optoelectronics, and optofluidics present a host of new challenges for optical device integration, which cannot be solved with existing bonding techniques. Here, we report a new method for substrate independent integration of dissimilar optical components by way of biological recognition-directed assembly. Bonding in this scheme is achieved by locally modifying the substrate with a protein receptor and the optical component with a biomolecular ligand or vice versa. The key features of this new technology include substrate independent assembly, cross-platform vertical scale integration, and selective registration of components based on complementary biomolecular interactions.
Using back focal plane interferometry to probe the influence of Zernike aberrations in optical tweezers
Publisher: The Optical Society
Date: 25-07-2017
DOI: 10.1364/OL.42.002968
Suppression of interdiffusion in InGaAs/GaAs quantum dots using dielectric layer of titanium dioxide
Publisher: AIP Publishing
Date: 14-04-2003
DOI: 10.1063/1.1569046
Abstract: In this work, titanium dioxide (TiO2) film was deposited onto the In0.5Ga0.5As/GaAs quantum-dot structure by electron-beam evaporation to investigate its effect on interdiffusion. A large redshifted and broadened spectrum from the dot emission was observed compared with that from the uncapped (but annealed) reference s le, indicating the suppression of thermal interdiffusion due to TiO2 deposition. The structure was also capped with a silicon dioxide (SiO2) single layer or SiO2/TiO2 bilayer with the thickness of SiO2 varied from ∼6 to ∼145 nm. In the former case, an increased amount of impurity-free vacancy disordering (IFVD) was introduced with the increase of SiO2 thickness due to the enhanced Ga outdiffusion into the film. With TiO2 deposited on top, IFVD and thermal interdiffusion were suppressed to different extents with the variation of SiO2 thickness. To explain the suppression of interdiffusion, thermal stress introduced by the large thermal expansion coefficient of TiO2 (when compared with GaAs) as well as the metallurgical reactions between the TiO2 and GaAs were proposed as possible mechanisms.
Efficient silicon light-emitting diodes
Publisher: Springer Science and Business Media LLC
Date: 08-2001
DOI: 10.1038/35090539
Extended organization of colloidal microparticles by surface plasmon polariton excitation
Publisher: American Physical Society (APS)
Date: 21-02-2006
Finer optical tweezers
Publisher: Springer Science and Business Media LLC
Date: 06-2008
Theoretical and experimental evaluation of silicon photonic structures for enhanced erbium up-conversion luminescence
Publisher: Elsevier BV
Date: 05-2013
Optical properties of II-VI colloidal quantum dot doped porous silicon microcavities
Publisher: AIP Publishing
Date: 19-04-2010
DOI: 10.1063/1.3404183
Abstract: In this paper we report on the light emitting properties of mesoporous silicon vertical-cavity optical resonators with II-VI colloidal quantum dots selectively deposited in the cavity layer. Optical resonator structures exhibit reflectivity stop bands of several hundred nanometres and resonant modes with line-widths less than 3.5 nm. The observed modification of spectral and spatial emission properties of the quantum dots and tenfold enhancement at the resonance wavelength is consistent with cavity enhanced spontaneous emission. Using this hybrid fabrication approach we show that narrow band light emitting structures may be fabricated over a broad spectral region in the visible and near-infrared.
Porous silicon: A photonic material for all seasons
Publisher: IEEE
Date: 2002
Optimizing Optical Tweezers Experiments for Magnetic Resonance Sensing with Nanodiamonds
Publisher: American Chemical Society (ACS)
Date: 15-03-2021
Biofunctionalization of free-standing porous silicon films for self-assembly of photonic devices
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C1SM06651J
Biophotonics feature: introduction
Publisher: The Optical Society
Date: 20-02-2018
DOI: 10.1364/BOE.9.001229
Protease detection using a porous silicon based Bloch surface wave optical biosensor
Publisher: Optica Publishing Group
Date: 30-06-2010
DOI: 10.1364/OE.18.015174
A rapid readout for many single plasmonic nanoparticles using dark-field microscopy and digital color analysis
Publisher: Elsevier BV
Date: 10-2018
DOI: 10.1016/J.BIOS.2018.06.066
Abstract: The integration of plasmonic nanoparticles into biosensors has the potential to increase the sensitivity and dynamic range of detection, through the use of single nanoparticle assays. The analysis of the localized surface plasmon resonance (LSPR) of plasmonic nanoparticles has allowed the limit of detection of biosensors to move towards single molecules. However, due to complex equipment or slow analysis times, these technologies have not been implemented for point-of-care detection. Herein, we demonstrate an advancement in LSPR analysis by presenting a technique, which utilizes an inexpensive CMOS-equipped digital camera and a dark-field microscope, that can analyse the λ
Fabricating low cost and high performance elastomer lenses using hanging droplets
Publisher: The Optical Society
Date: 24-04-2014
DOI: 10.1364/BOE.5.001626
Exploration of sub-bandgap states in 2D halide perovskite single-crystal photodetector
Publisher: Springer Science and Business Media LLC
Date: 23-06-2022
DOI: 10.1038/S41699-022-00317-5
Abstract: Greater stability of low-dimensional halide perovskites as opposed to their three-dimensional counterparts, alongside their high extinction coefficient and thus excellent emission properties, have made them popular candidates for optoelectronic applications. Topological edges are found in two-dimensional perovskites that show distinct electronic properties. In this work, using Kelvin Probe Force Microscopy, performed on butylammonium lead bromide (BA 2 PbBr 4 ) single crystals with optical bandgap of ~413 nm, we elucidate the electronic response of the edges and their potential impact on photodetector devices. We show that the charge-carriers are accumulated at the edges, increasing with the edge height. Wavelength-dependent surface photovoltage (SPV) measurements reveal that multiple sub-bandgap states exist in BA 2 PbBr 4 . As the edge height increases, the SPV litude at the edges reduces slightly more as compared to the adjacent regions, known as terraces, indicating relatively less reduction in band-bending at the surface due possibly to increased de-population of electrons from sub-bandgap states in the upper bandgap half. The existence of sub-bandgap states is further confirmed by the observation of below-bandgap emission (absorption) peaks characterised by spectral photoluminescence and photothermal deflection spectroscopy measurements. Finally, we fabricated a photodetector using a millimetre size BA 2 PbBr 4 single crystal. Noticeable broadband photodetection response was observed in the sub-bandgap regions under green and red illumination, which is attributed to the existence of sub-bandgap states. Our observations suggest edge-height dependence of charge-carrier behaviour in BA 2 PbBr 4 single crystals, a potential pathway that can be exploited for efficient broadband photodetector fabrication.
Spectroscopy of 3D-trapped particles inside a hollow-core microstructured optical fiber
Publisher: The Optical Society
Date: 05-2012
DOI: 10.1364/OE.20.011232
Impurity-free vacancy disordering of quantum wells and quantum dots for optoelectronic/photonic integrated circuits
Publisher: IEEE
Date: 09-2004
Noise induced aperiodic rotations of particles trapped by a non-conservative force
Publisher: AIP Publishing
Date: 04-2018
DOI: 10.1063/1.5018443
Abstract: We describe a mechanism whereby random noise can play a constructive role in the manifestation of a pattern, aperiodic rotations, that would otherwise be d ed by internal dynamics. The mechanism is described physically in a theoretical model of overd ed particle motion in two dimensions with symmetric d ing and a non-conservative force field driven by noise. Cyclic motion only occurs as a result of stochastic noise in this system. However, the persistence of the cyclic motion is quantified by parameters associated with the non-conservative forcing. Unlike stochastic resonance or coherence resonance, where noise can play a constructive role in lifying a signal that is otherwise below the threshold for detection, in the mechanism considered here, the signal that is detected does not exist without the noise. Moreover, the system described here is a linear system.
Photoluminescence study of optically trapped InP semiconductor nanowires
Publisher: SPIE
Date: 19-08-2010
DOI: 10.1117/12.860236
Semiconductor nanostructures towards electronic and opto‐electronic device applications V
Publisher: Wiley
Date: 12-2015
Optical micromanipulation
Publisher: Royal Society of Chemistry (RSC)
Date: 2008
DOI: 10.1039/B512471A
Abstract: Optical micromanipulation has engendered some major studies across all of the natural sciences at the mesoscopic scale. Though over thirty-five years old, the field is finding new applications and has lost none of its dynamic or innovative character: a trapped object presents a system that enables a calibrated minuscule force (piconewtons or less) to be exerted at will, enabling precision displacements right down to the angstrom level to be observed. The study of the motion of single biological molecular motors has been revolutionised and new studies in the physical sciences have been realised. From the chemistry and microfluidic viewpoint, optical forces may remotely actuate micro-components and perform micro-reactions. Overall, optical traps are becoming a key part of a wider "optical toolkit". We present a tutorial review of this technique, its fundamental principles and a flavour of some of the recent advances made.
Versatile click chemistry Approach to functionalizing silicon quantum dots: Applications toward fluorescent cellular imaging
Publisher: American Chemical Society (ACS)
Date: 28-04-2014
DOI: 10.1021/LA500945F
Abstract: In this study, we describe a solution procedure for the preparation and surface modification of photostable colloidal silicon quantum dots (SiQDs) for imaging of cancer cells. Photoluminescent SiQDs were synthesized by reduction of halogenated silane precursors using a microemulsion process. It was shown that 1,8-nonadiyne molecules could be grafted onto the surface of hydrogen-terminated SiQDs via ultraviolet (UV)-promoted hydrosilylation, demonstrated by Fourier transform infrared spectroscopy (FTIR) measurements. In addition, various azide molecules were coupled onto nonadiyne-functionalized particles, rendering particles dispersible in selected polar and nonpolar solvents. The photoluminescence of functionalized SiQDs was stable against photobleaching and did not vary appreciably within biologically applicable pH and temperature ranges. To demonstrate compatibility with biological systems, water-soluble SiQDs were used for fluorescent imaging of HeLa cells. In addition, the SiQDs were shown to be non-cytotoxic at concentrations up to 240 μg/mL. The results presented herein provide good evidence for the versatility of functionalized SiQDs for fluorescent bioimaging application.
Origin of gate hysteresis in p-type Si-doped AlGaAs/GaAs heterostructures
Publisher: American Physical Society (APS)
Date: 08-10-2012
Proton-irradiation-induced intermixing of InGaAs quantum dots
Publisher: AIP Publishing
Date: 25-03-2003
DOI: 10.1063/1.1561153
Abstract: Proton irradiation was used to create interdiffusion in In0.5Ga0.5As quantum dots (QDs), grown by low-pressure metalorganic chemical vapor deposition. After 25-keV proton irradiation, the QD s les were annealed at two temperatures (700 or 750 °C) for 30 s. It was found that much lower annealing temperatures were needed to recover the photoluminescence signals than in the quantum-well case. Large blueshifts (120 meV) and narrowing of the photoluminescence spectra were seen. Various doses (5×1013–1×1015 cm−2) and implant temperatures (20–200 °C) were used to study the interdiffusion processes in these s les. In QD s les, much lower doses were required to achieve similar energy shifts than reported in quantum-well s les.
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Discovery Projects - Grant ID: DP110102183
Start Date: 2011
End Date: 02-2015
Amount: $540,000.00
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Start Date: 2014
End Date: 12-2015
Amount: $150,000.00
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View Funded ActivityLinkage Infrastructure, Equipment And Facilities - Grant ID: LE200100098
Start Date: 2020
End Date: 06-2022
Amount: $600,000.00
Funder: Australian Research Council
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