ORCID Profile
0000-0003-4638-273X
Current Organisation
UNSW Sydney
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Publisher: Institution of Engineering and Technology (IET)
Date: 1992
Publisher: SPIE
Date: 07-07-1998
DOI: 10.1117/12.316720
Publisher: SPIE
Date: 07-07-1998
DOI: 10.1117/12.316721
Publisher: The Optical Society
Date: 07-1997
Publisher: The Optical Society
Date: 1991
DOI: 10.1364/OL.16.000021
Abstract: To be self-guided, a beam must exactly equal the mode of the linear-optical fiber that it induces. From this elementary consistency condition we can borrow solutions and their associated physics directly from the familiar literature of linear-optical waveguides. By considering a nonlinear medium characterized by ideal saturation, we present what is to our knowledge the first exact analytical solution of a two-dimensional self-guided beam. This beam is the familiar fundamental mode of a step-profile fiber. The stability of the beam is also determined.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 12-1999
DOI: 10.1109/68.806865
Publisher: Elsevier BV
Date: 04-2011
Publisher: Wiley
Date: 2007
DOI: 10.1002/JEMT.20405
Abstract: The evanescent field surrounding an exposed planar waveguide in silica is accurately measured using scanning near field optical microscopy (SNOM) and compared to models of the field distribution. Distortions in the field due to edge effects and the proximity of the mode to the surface are all detected. The characterized field is use to quantitatively explore the difference in collection efficiency between contact mode SNOM and intermittent contact mode SNOM. A strong correlation between tip oscillation litude and detection efficiency is determined.
Publisher: IOP Publishing
Date: 21-02-2011
Publisher: Elsevier BV
Date: 2013
Publisher: Springer Science and Business Media LLC
Date: 1999
Publisher: Elsevier BV
Date: 04-2016
Publisher: AIP Publishing
Date: 09-2023
DOI: 10.1063/5.0153753
Publisher: IEEE
Date: 12-2014
Publisher: Springer Science and Business Media LLC
Date: 09-02-2018
DOI: 10.1038/S41598-018-20182-X
Abstract: We propose an optical electrode ’optrode’ sensor array for biopotential measurements. The transduction mechanism is based on deformed helix ferroelectric liquid crystals which realign, altering the optrode’s light reflectance properties, relative to applied potential fields of biological cells and tissue. A computational model of extracellular potential recording by the optrode including the electro-optical transduction mechanism is presented, using a combination of time-domain and frequency-domain finite element analysis. Simulations indicate that the device has appropriate temporal response to faithfully transduce neuronal spikes, and spatial resolution to capture impulse propagation along a single neuron. These simulations contribute to the development of multi-channel optrode arrays for spatio-temporal mapping of electric events in excitable biological tissue.
Publisher: Institution of Engineering and Technology (IET)
Date: 1992
DOI: 10.1049/EL:19920839
Publisher: The Optical Society
Date: 2007
DOI: 10.1364/OE.15.009989
Abstract: A novel and highly versatile doping method has been developed to allow active dopants, including materials incompatible with the polymer matrix, to be incorporated into microstructured polymer optical fibers through the use of nanoparticles. The incorporation of quantum dots and silica nanoparticles containing Rhodamine isothiocyanate is demonstrated.
Publisher: Springer Science and Business Media LLC
Date: 12-1992
DOI: 10.1007/BF00625813
Publisher: The Optical Society
Date: 20-04-2000
DOI: 10.1364/AO.39.001966
Abstract: The scanning near-field optical microscope (SNOM) has been tested experimentally for a wide variety of applications, but, to date, there has been little work done on the numerical or analytical modeling of the optical field as it propagates throughout the SNOM probe. Therefore, the fabrication on the probes relies more on trial and error than on clear design principles. An algorithm has been developed for the study and optimization of the geometry of SNOM probes fabricated by the heat-drawn and the one-step chemically etched methods. The algorithm uses the finite-difference beam propagation method (FD-BPM) to model the field evolution throughout the SNOM structure.
Publisher: American Chemical Society (ACS)
Date: 20-01-2010
DOI: 10.1021/CM9034165
Publisher: Institution of Engineering and Technology (IET)
Date: 2006
DOI: 10.1049/EL:20060744
Publisher: Elsevier BV
Date: 12-2017
Publisher: OSA
Date: 2016
Publisher: SPIE
Date: 30-12-2019
DOI: 10.1117/12.2539894
Publisher: AIP Publishing
Date: 30-07-2012
DOI: 10.1063/1.4742736
Publisher: SPIE
Date: 30-12-2019
DOI: 10.1117/12.2544053
Publisher: Institution of Engineering and Technology (IET)
Date: 1992
DOI: 10.1049/EL:19920137
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 1998
DOI: 10.1109/68.651124
Publisher: American Chemical Society (ACS)
Date: 12-04-2016
DOI: 10.1021/ACS.JPCLETT.6B00285
Abstract: We present a comprehensive first-principles study of the band alignment at AlN(0001)/diamond(100) heterojunctions, considering two different polarities of the AlN and taking into account atomic relaxation at the interface. Our simulations show that the valence-band offset reduces dramatically from about 1.6 eV for one polarity to 0.6 eV for the other, changing the corresponding band alignment from staggered (type II) to straddling (type I). Our findings have important consequences for the design of many applications, most notably solid state UV-emitting devices.
Publisher: Optica Publishing Group
Date: 02-06-2021
DOI: 10.1364/OE.426503
Abstract: We propose a new mode of operation when using a photodiode to extract a variable optical signal from a constant (ambient) background. The basic idea of this ‘zero-mode’ of operation is to force the photodiode to operate at either zero current or zero voltage. We present possible implementations of this novel approach and provide the corresponding equivalent circuits while also demonstrating experimentally its performance. The gain and bandwidth of the zero-mode photodetector are measured and simulated, and they show highly agreement. The gain compression effect because of the nonlinearity of the forward bias region is also explored. Comparing to the conventional photoconductive photodetector, the zero-mode photodetector is able to obtain higher AC gain and lower noise. With the same component used in the circuit, the measured input referred root mean square noise of zero-mode photodetector is 4.4mV whereas that of the photoconductive mode photodetector is 96.9mV respectively, showing the feasibility of the zero-mode of operation for measuring the small variable light signal under a high power constant background light.
Publisher: The Optical Society
Date: 25-08-2009
DOI: 10.1364/OE.17.015983
Publisher: Elsevier BV
Date: 07-2013
Publisher: Springer Science and Business Media LLC
Date: 04-1995
DOI: 10.1007/BF00631752
Publisher: The Optical Society
Date: 17-04-2009
DOI: 10.1364/OE.17.007295
Abstract: To take existing quantum optical experiments and devices into a more practical regimes requires the construction of robust, solid-state implementations. In particular, to observe the strong-coupling regime of tom-photon interactions requires very small cavities and large quality factors. Here we show that the slot-waveguide geometry recently introduced for photonic applications is also promising for quantum optical applications in the visible regime. We study diamond- and GaP-based slot-waveguide cavities (SWCs) compatible with diamond colour centres e.g. nitrogen-vacancy (NV) defect. We show that one can achieve increased single-photon Rabi frequencies of order O(10(11)) rad s(-1) in ultra-small cavity modal volumes, nearly 2 orders of magnitude smaller than previously studied diamond-based photonic crystal cavities.
Publisher: The Optical Society
Date: 15-08-1997
DOI: 10.1364/OL.22.001241
Abstract: We examine the assumption of adiabaticity that underlies mode-coupling analysis of stochastic phenomena such as roughness and inhomogeneity in passive photonics devices such as couplers, gratings, and simple waveguides. We show that although the adiabaticity condition is formally violated by such phenomena, only the low spatial frequencies actually contribute significantly to such phenomena, thus preserving the validity of the analysis.
Publisher: OSA
Date: 2018
Publisher: The Optical Society
Date: 06-1997
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 09-2019
Publisher: Institution of Engineering and Technology (IET)
Date: 1991
Publisher: SPIE-Intl Soc Optical Eng
Date: 10-11-2021
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C1PY00056J
Publisher: SPIE
Date: 07-07-1998
DOI: 10.1117/12.316730
Publisher: IOP Publishing
Date: 23-11-2010
DOI: 10.1088/0953-8984/22/49/494105
Abstract: We have assessed the potential of self-assembling hydrogels for use in conformal displays. The self-assembling process can be used to alter the transparency of the material to all visible light due to scattering by fibres. The reversible transition is shown to be of low energy by differential scanning calorimetry. For use in technology it is imperative that this transition is controlled electrically. We have thus synthesized novel self-assembling hydrogelator molecules which contain an electroactive group. The well-known redox couple of anthraquinone/anthrahydroquinone has been used as the hydrophobic component for a series of small molecule gelators. They are further functionalized with peptide combinations of L-phenylalanine and glycine to provide the hydrophilic group to complete 'head-tail' models of self-assembling gels. The gelation and electroactive characteristics of the series were assessed. Cyclic voltammetry shows the reversible redox cycle to be only superficially altered by functionalization. Additionally, spectroelectrochemical measurements show a reversible transparency and colour change induced by the redox process.
Publisher: American Chemical Society (ACS)
Date: 26-06-2013
DOI: 10.1021/CG400383T
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 09-2013
Publisher: The Optical Society
Date: 1996
DOI: 10.1364/OL.21.000004
Abstract: A new beam-propagation scheme based on a finite-difference algorithm is proposed. The main property of this scheme is to avoid the boundary conditions altogether, by mapping the infinite space onto a finite-size domain. This mapping, together with a rescaling of the field, leads to a fast and easy-to-implement algorithm that can be used when boundary condition constraints are important.
Publisher: Springer Science and Business Media LLC
Date: 14-01-2010
Publisher: IEEE
Date: 08-2012
Publisher: SPIE
Date: 30-12-2019
DOI: 10.1117/12.2539997
Publisher: SPIE
Date: 09-12-2016
DOI: 10.1117/12.2242866
Publisher: Informa UK Limited
Date: 1989
Publisher: Springer Science and Business Media LLC
Date: 09-1990
DOI: 10.1007/BF02113969
Publisher: OSA
Date: 2018
Publisher: Elsevier BV
Date: 03-2021
Publisher: Institution of Engineering and Technology (IET)
Date: 1997
DOI: 10.1049/EL:19971137
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-2023
Publisher: The Optical Society
Date: 15-03-2007
Publisher: Elsevier BV
Date: 2011
Publisher: The Optical Society
Date: 11-03-2019
DOI: 10.1364/OE.27.008777
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 06-1997
DOI: 10.1109/50.588676
Publisher: IEEE
Date: 08-2016
Publisher: Institution of Engineering and Technology (IET)
Date: 1997
DOI: 10.1049/EL:19970609
Publisher: Institution of Engineering and Technology (IET)
Date: 1996
DOI: 10.1049/EL:19960254
Publisher: Springer Science and Business Media LLC
Date: 26-04-2022
DOI: 10.1007/S40789-022-00496-Y
Abstract: We present an optically powered, intrinsically safe gas monitoring system to measure four essential environmental gases (CH 4 , CO 2 , CO and O 2 ), together with ambient temperature and pressure, for underground mines. The system is based on three key technologies developed at UNSW: (1) power-over-fibre (PoF) at 1550 nm using a single industry-standard, low-cost single-mode fibre (SMF) for both power delivery and information transmission, (2) liquid–crystal-based optical transducers for optical telemetry, and (3) ultra-low power consumption design of all electronics. Together, this approach allows each gas monitoring station to operate with less than 150 mW of optical power, meeting the intrinsic safety requirements specified by the IEC60079-28 standard. A 2-month field trial at BMA’s Broadmeadow underground mine proved the cabling compatibility to the mine’s existing optical network and the stability of the system performance. Compared with conventional electrically powered gas sensors, this technology bypasses the usual roadblocks of underground gas monitoring where electrical power is either unsafe or unavailable. Furthermore, using one fibre for both power delivery and communication enables longer distance coverage, reduces optical cabling and increases multiplexing possibilities and data throughput for better awareness of underground environment.
Publisher: The Optical Society
Date: 10-11-2008
DOI: 10.1364/OE.16.019512
Abstract: We demonstrate for the first time the feasibility of all-diamond integrated optic devices over large areas using a combination of photolithography, reactive ion etching (RIE) and focused ion beam (FIB) techniques. We confirm the viability of this scalable process by demonstrating guidance in a two-moded ridge waveguide in type 1b single crystal diamond. This opens the door to the fabrication of a diamond-based optical chip integrating functional elements such as X-crossings, Y-junctions, evanescent couplers, Bragg reflectors/couplers and various interferometers.
Publisher: Springer Science and Business Media LLC
Date: 1994
DOI: 10.1007/BF00573900
Publisher: SPIE
Date: 11-02-2010
DOI: 10.1117/12.843013
Publisher: IOP Publishing
Date: 03-07-1989
Publisher: IEEE
Date: 06-2007
Publisher: American College of Physicians
Date: 06-11-2001
DOI: 10.7326/0003-4819-135-9-200111060-00008
Abstract: Studies relating certain chemokine and chemokine receptor gene alleles with the outcome of HIV-1 infection have yielded inconsistent results. To examine postulated associations of genetic alleles with HIV-1 disease progression. Meta-analysis of in idual-patient data. 19 prospective cohort studies and case-control studies from the United States, Europe, and Australia. Patients with HIV-1 infection who were of European or African descent. Time to AIDS, death, and death after AIDS and HIV-1 RNA level at study entry or soon after seroconversion. Data were combined with fixed-effects and random-effects models. Both the CCR5-Delta32 and CCR2-64I alleles were associated with a decreased risk for progression to AIDS (relative hazard among seroconverters, 0.74 and 0.76, respectively P = 0.01 for both), a decreased risk for death (relative hazard among seroconverters, 0.64 and 0.74 P < 0.05 for both), and lower HIV-1 RNA levels after seroconversion (difference, -0.18 log(10) copies/mL and -0.14 log(10) copies/mL P 0.5 for all). The CCR5-Delta32 and CCR2-64I alleles had a strong protective effect on progression of HIV-1 infection, but SDF-1 3'A homozygosity carried no such protection.
Publisher: IOP Publishing
Date: 10-2022
Abstract: Objective. Biomedical instrumentation and clinical systems for electrophysiology rely on electrodes and wires for sensing and transmission of bioelectric signals. However, this electronic approach constrains bandwidth, signal conditioning circuit designs, and the number of channels in invasive or miniature devices. This paper demonstrates an alternative approach using light to sense and transmit the electrophysiological signals. Approach. We develop a sensing, passive, fluorophore-free optrode based on the birefringence property of liquid crystals (LCs) operating at the microscale. Main results. We show that these optrodes can have the appropriate linearity ( µ ± s.d.: 99.4 ± 0.5%, n = 11 devices), relative responsivity ( µ ± s.d.: 57 ± 12%V −1 , n = 5 devices), and bandwidth ( µ ± s.d.: 11.1 ± 0.7 kHz, n = 7 devices) for transducing electrophysiology signals into the optical domain. We report capture of rabbit cardiac sinoatrial electrograms and stimulus-evoked compound action potentials from the rabbit sciatic nerve. We also demonstrate miniaturisation potential by fabricating multi-optrode arrays, by developing a process that automatically matches each transducer element area with that of its corresponding biological interface. Significance. Our method of employing LCs to convert bioelectric signals into the optical domain will pave the way for the deployment of high-bandwidth optical telecommunications techniques in ultra-miniature clinical diagnostic and research laboratory neural and cardiac interfaces.
Publisher: The Optical Society
Date: 11-06-2012
DOI: 10.1364/OL.37.002343
Publisher: The Optical Society
Date: 17-05-2007
Publisher: SPIE
Date: 23-01-1997
DOI: 10.1117/12.264175
Publisher: Springer Science and Business Media LLC
Date: 10-1995
DOI: 10.1007/BF00558490
Publisher: The Optical Society
Date: 15-11-1996
DOI: 10.1364/OL.21.001833
Abstract: Surface roughness is normally considered to be the main cause of attenuation in intergrated-optics glass waveguides. Previous analyses have concentrated on scattering of light into the radiation field in fact, depending on the roughness length scale, scattering can be predominantly in the backward direction, raising the question of how important the coupling with the backward-directed bound mode is. We investigate this effect and show that it can be neglected in most circumstances.
Publisher: IEEE
Date: 07-2008
Publisher: American Physical Society (APS)
Date: 27-11-2018
Publisher: Institution of Engineering and Technology (IET)
Date: 2000
DOI: 10.1049/EL:20000814
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 05-2022
Publisher: Institution of Engineering and Technology (IET)
Date: 08-1994
Publisher: SPIE
Date: 21-12-2007
DOI: 10.1117/12.769906
Publisher: The Optical Society
Date: 21-03-2011
DOI: 10.1364/OE.19.006354
Publisher: The Optical Society
Date: 09-2006
DOI: 10.1364/AO.45.006442
Abstract: We analyze two basic aspects of a scanning near-field optical microscope (SNOM) probe's operation: (i) spot-size evolution of the electric field along the probe with and without a metal layer, and (ii) a modal analysis of the SNOM probe, particularly in close proximity to the aperture. A slab waveguide model is utilized to minimize the analytical complexity, yet provides useful quantitative results--including losses associated with the metal coating--which can then be used as design rules.
Publisher: AIP Publishing
Date: 19-09-2011
DOI: 10.1063/1.3641861
Abstract: The properties of Si and O donors in wurtzite AlN have been studied by means of hybrid functional calculations, finding that both impurities form DX centres. In the case of Si, the stable DX centre is close in energy to the substitutional donor state and to a second metastable DX centre, thus explaining both the persistent effects and the broad range of activation energies observed experimentally. Ionisation energies have been computed for both Si and O donor states.
Publisher: SPIE
Date: 09-06-1998
DOI: 10.1117/12.311537
Publisher: The Optical Society
Date: 02-1999
Publisher: SPIE
Date: 30-12-2019
DOI: 10.1117/12.2540053
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 03-1995
DOI: 10.1109/50.372446
Publisher: Springer Science and Business Media LLC
Date: 2002
Publisher: SPIE
Date: 31-01-2012
DOI: 10.1117/12.915970
Publisher: Informa UK Limited
Date: 14-06-2013
Publisher: The Optical Society
Date: 15-03-2007
Publisher: Institution of Engineering and Technology (IET)
Date: 1995
Publisher: Elsevier BV
Date: 10-2012
Publisher: SPIE
Date: 30-12-2019
DOI: 10.1117/12.2539900
Publisher: IEEE
Date: 06-2007
Publisher: SPIE
Date: 08-04-1996
DOI: 10.1117/12.237769
Publisher: Elsevier BV
Date: 06-2017
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 03-1995
DOI: 10.1109/50.372431
Publisher: The Optical Society
Date: 23-01-2017
DOI: 10.1364/OE.25.001692
Publisher: Elsevier BV
Date: 11-2008
Publisher: SPIE
Date: 17-02-2020
DOI: 10.1117/12.2544087
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 12-2021
Publisher: IOP Publishing
Date: 05-2012
Publisher: SPIE
Date: 31-01-2012
DOI: 10.1117/12.915962
Publisher: Springer Science and Business Media LLC
Date: 10-07-2012
No related grants have been discovered for Francois Ladouceur.