ORCID Profile
0000-0001-6534-9009
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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)
Optical Physics | Photonics, Optoelectronics and Optical Communications | Lasers and Quantum Electronics | Nonlinear optics and spectroscopy | Atomic molecular and optical physics | Photonic and electro-optical devices sensors and systems (excl. communications) | Electronics sensors and digital hardware | Atomic molecular and optical physics not elsewhere classified | Nanofabrication growth and self assembly | Astronomical instrumentation | Photonics optoelectronics and optical communications
ANZSRC Socio-Economic Objective (SEO)
Expanding Knowledge in the Physical Sciences | Scientific Instruments |
Related Links
Publications
Micromanipulation with Bessel beams: studies of angular momentum and reconstruction
Publisher: SPIE
Date: 18-10-2004
DOI: 10.1117/12.556319
Widefield light sheet microscopy using an Airy beam combined with deep-learning super-resolution
Publisher: Optica Publishing Group
Date: 14-04-2020
DOI: 10.1364/OSAC.391644
Transient transfection of mammalian cells using a violet diode laser
Publisher: SPIE-Intl Soc Optical Eng
Date: 2010
DOI: 10.1117/1.3430730
Abstract: We demonstrate the first use of the violet diode laser for transient mammalian cell transfection. In contrast to previous studies, which showed the generation of stable cell lines over a few weeks, we develop a methodology to transiently transfect cells with an efficiency of up to approximately 40%. Chinese hamster ovary (CHO-K1) and human embryonic kidney (HEK293) cells are exposed to a tightly focused 405-nm laser in the presence of plasmid DNA encoding for a mitochondrial targeted red fluorescent protein. We report transfection efficiencies as a function of laser power and exposure time for our system. We also show, for the first time, that a continuous wave laser source can be successfully applied to selective gene silencing experiments using small interfering RNA. This work is a major step towards an inexpensive and portable phototransfection system.
Modal beam splitter: determination of the transversal components of an electromagnetic light field
Publisher: Springer Science and Business Media LLC
Date: 22-08-2017
DOI: 10.1038/S41598-017-08657-9
Abstract: The transversal profile of beams can always be defined as a superposition of orthogonal fields, such as optical eigenmodes. Here, we describe a generic method to separate the in idual components in a laser beam and map each mode onto its designated detector with low crosstalk. We demonstrate this with the decomposition into Laguerre-Gaussian beams and introduce a distribution over the integer numbers corresponding to the discrete orbital and radial momentum components of the light field. The method is based on determining an eigenmask filter transforming the incident optical eigenmodes to position eigenmodes enabling the detection of the state of the light field using single detectors while minimizing cross talk with respect to the set of filter masks considered.
Spatially offset optical coherence tomography: Leveraging multiple scattering for high-contrast imaging at depth in turbid media
Publisher: American Association for the Advancement of Science (AAAS)
Date: 07-07-2023
Phase conjugation and four-wave mixing in a colloidal medium
Publisher: SPIE
Date: 31-08-2006
DOI: 10.1117/12.677222
Controlled three-dimensional manipulation of vanadium oxide nanotubes with optical tweezers
Publisher: AIP Publishing
Date: 15-12-2008
DOI: 10.1063/1.3039407
Abstract: We present a direct nanotube-microsphere tagging technique for the controlled three-dimensional (3D) manipulation and transportation of vanadium oxide nanotubes (VOx-NTs) with optical tweezers. The high scattering and absorptive nature of the VOx-NTs preclude the 3D optical trapping of such nanostructures. VOx-NTs are adhered to 3-aminopropyl-triethoxysilane functionalized silica microspheres, which act as handles for indirectly manipulating and transporting the nanotubes in three dimensions with optical tweezers. The optical tweezers can also operate as optical scissors that can remove the dielectric handles and trim these nanotubes. This technique may be extended to the optical manipulation of nanotubes of any material.
UVA hyperspectral light-sheet microscopy for volumetric metabolic imaging: application to pre-implantation embryo development
Publisher: Cold Spring Harbor Laboratory
Date: 22-06-2023
DOI: 10.1101/2023.06.21.545939
Abstract: Cellular metabolism is a key regulator of energetics, cell growth, regeneration and homeostasis. Spatially mapping the heterogeneity of cellular metabolic activity is of great importance for unraveling the overall cell and tissue health. In this regard, imaging the endogenous metabolic co-factors NAD(P)H and FAD with sub-cellular resolution and in a non-invasive manner would be useful to determine tissue and cell viability in a clinical environment, but practical use is limited by current imaging techniques. In this article, we demonstrate the use of phasor-based hyperspectral light-sheet (HS-LS) microscopy using a single UVA excitation wavelength as a route to mapping metabolism in three dimensions. We show that excitation solely at a UVA wavelength of 375 nm can simultaneously excite NAD(P)H and FAD autofluorescence, while their relative contributions can be readily quantified using a hardware-based spectral phasor analysis. We demonstrate the potential of our HS-LS system by capturing dynamic changes in metabolic activity during pre-implantation embryo development. To validate our approach, we delineate metabolic changes during pre-implantation embryo development from volumetric maps of metabolic activity. Importantly, our approach overcomes the need for multiple excitation wavelengths, two-photon imaging or significant post-processing of data, paving the way towards clinical translation, such as in situ, non-invasive assessment of embryo viability.
Intracellular Dielectric Tagging for Improved Optical Manipulation of Mammalian Cells
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2010
Optically bound arrays of microscopic particles in one dimension
Publisher: SPIE
Date: 18-10-2004
DOI: 10.1117/12.555663
Optical trapping and spectral analysis of aerosols with a supercontiuum laser source
Publisher: Optica Publishing Group
Date: 12-05-2008
DOI: 10.1364/OE.16.007655
Abstract: We report on the optical trapping of water droplets with a supercontinuum laser source. Droplet size is determined by observing the spectrum of the on-axis backscattered light. In contrast to to monochromatic trapping, the broad spectrum of the supercontinuum covers several resonances of the first excited Mie coefficients. A minimum value of Q approximately 0.16 for the trapping efficiency is estimated.
Investigation of refractive index dynamics during embryo development using digital holographic microscopy
Publisher: Cold Spring Harbor Laboratory
Date: 18-04-2023
DOI: 10.1101/2023.04.17.537152
Abstract: Embryo quality is a crucial factor affecting live birth outcomes. However, an accurate diagnostic for embryo quality remains elusive in the in vitro fertilization clinic. Determining physical parameters of the embryo may offer key information for this purpose. Here, we demonstrate that digital holographic microscopy (DHM) can rapidly and non-invasively assess the refractive index of mouse embryos. We showed that DHM can detect spatio-temporal changes in refractive index during embryo development that are reflective of its lipid content. As accumulation of intracellular lipid is known to compromise embryo health, DHM may prove beneficial in developing an accurate, non-invasive, multimodal diagnostic.
Bessel beams: Diffraction in a new light
Publisher: Informa UK Limited
Date: 2005
Near-field optical trapping with an ultrashort pulsed laser beam
Publisher: AIP Publishing
Date: 25-02-2008
DOI: 10.1063/1.2888771
Abstract: We report the focused evanescent optical trapping of nonfluorescent and fluorescent dielectric microspheres using a femtosecond laser. The experiment confirms that the trapping efficiency increases with the size of the particles. As a result, a pulsed laser has been used to trap particles in the Mie regime and to excite whispering gallery modes in them. The excitation of whispering gallery modes in a near-field femtosecond trap shows a significant suppression of the two-photon fluorescence background with an improvement of the photon storage factor by 46%, as compared to far-field two-photon excitation.
Advanced micromanipulation using bessel beams
Publisher: IEEE
Date: 2003
Guiding a cold atomic beam along a co-propagating and oblique hollow light guide
Publisher: Elsevier BV
Date: 12-2002
Emergent physics-informed design of deep learning for microscopy
Publisher: IOP Publishing
Date: 04-2021
Experimental Observation of Modulation Instability and Optical Spatial Soliton Arrays in Soft Condensed Matter
Publisher: American Physical Society (APS)
Date: 18-05-2007
Imaging in optical micromanipulation using two-photon excitation
Publisher: IOP Publishing
Date: 22-10-2004
Interfering Bessel beams for optical micromanipulation
Publisher: Optica Publishing Group
Date: 15-04-2003
DOI: 10.1364/OL.28.000657
Abstract: We examine the properties of interfering high-order Bessel beams. We implement an experimental setup that allows us to realize these interferograms, using interfering Laguerre-Gaussian beams and an axicon. We demonstrate the use of such beams for controlled rotation of microscopic particles in optical tweezers and rotators. The self-healing properties of interfering Bessel beams allow the simultaneous manipulation and rotation of particles in spatially separated s le cells.
Near-Field Optical Micromanipulation
Publisher: Elsevier
Date: 2008
Three-dimensional arrays of optical bottle beams
Publisher: Elsevier BV
Date: 10-2003
A compact light-sheet microscope for the study of the mammalian central nervous system
Publisher: Springer Science and Business Media LLC
Date: 24-05-2016
DOI: 10.1038/SREP26317
Abstract: Investigation of the transient processes integral to neuronal function demands rapid and high-resolution imaging techniques over a large field of view, which cannot be achieved with conventional scanning microscopes. Here we describe a compact light sheet fluorescence microscope, featuring a 45° inverted geometry and an integrated photolysis laser, that is optimized for applications in neuroscience, in particular fast imaging of sub-neuronal structures in mammalian brain slices. We demonstrate the utility of this design for three-dimensional morphological reconstruction, activation of a single synapse with localized photolysis, and fast imaging of neuronal Ca 2+ signalling across a large field of view. The developed system opens up a host of novel applications for the neuroscience community.
Nonlinear optical response of colloidal suspensions
Publisher: Optica Publishing Group
Date: 04-06-2009
DOI: 10.1364/OE.17.010277
Abstract: We experimentally probed the nonlinear optical response of aqueous nano-colloidal suspensions to provide a test of the theoretical approaches that have been proposed for the nonlinearity, namely an exponential model, an artificial Kerr medium, and a non-ideal gas model. The best agreement with experiment is found using the non-ideal gas model for the colloidal suspension which in turn can be used to infer values for the second virial coefficient of the medium and the nonlinear coefficients.
Optical trapping of NaYF4:Er3+,Yb3+ upconverting fluorescent nanoparticles
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3NR03644H
Abstract: We report on the first experimental observation of stable optical trapping of dielectric NaYF4:Er(3+),Yb(3+) upconverting fluorescent nanoparticles (~26 nm in diameter) using a continuous wave 980 nm single-beam laser. The laser serves both to optically trap and to excite visible luminescence from the nanoparticles. Sequential loading of in idual nanoparticles into the trap is observed from the analysis of the emitted luminescence. We demonstrate that the trapping strength and the number of in idual nanoparticles trapped are dictated by both the laser power and nanoparticle density. The possible contribution of thermal effects has been investigated by performing trapping experiment in both heavy water and into distilled water. For the case of heavy water, thermal gradients are negligible and optical forces dominate the trap loading behaviour. The results provide a promising path towards real three dimensional manipulation of single NaYF4:Er(3+),Yb(3+) nanoparticles for precise fluorescence sensing in biophotonics experiments.
The Application of Optical Coherence Tomography to Image Subsurface Tissue Structure of Antarctic Krill Euphausia superba
Publisher: Public Library of Science (PLoS)
Date: 13-10-2014
Optical sorting of gold nanoparticles based on the red-shift of plasmon resonance
Publisher: SPIE
Date: 09-10-2012
DOI: 10.1117/12.928482
Optical levitation in a Bessel light beam
Publisher: AIP Publishing
Date: 11-2004
DOI: 10.1063/1.1814820
Abstract: A vertically oriented zero order Bessel light beam is shown to create a one-dimensional array of trapped particles over extended (millimeter) distances. The particles take up equilibrium positions over the entire length of the beam and this is a consequence of the interplay between optical scattering and the self-healing properties of the Bessel beam. This work has analogies to recent studies of optically bound matter and allows for the simple creation of one-dimensional particle chains and their subsequent spectroscopic analysis.
The reconstruction of optical angular momentum after distortion in amplitude, phase and polarization
Publisher: IOP Publishing
Date: 20-04-2004
Colloidal dynamics in the circularly symmetric optical potential of a Bessel beam
Publisher: SPIE
Date: 18-08-2005
DOI: 10.1117/12.614416
Optical tweezers with increased axial trapping efficiency
Publisher: Informa UK Limited
Date: 09-1998
Far field interference measurements of vortex light fields in optical trapping
Publisher: SPIE
Date: 08-02-2007
DOI: 10.1117/12.702215
Experimentally unsupervised deconvolution for light-sheet microscopy with propagation-invariant beams
Publisher: Cold Spring Harbor Laboratory
Date: 27-05-2021
DOI: 10.1101/2021.05.26.445797
Abstract: Deconvolution is a challenging inverse problem, particularly in techniques that employ complex engineered point-spread functions, such as microscopy with propagation-invariant beams. Here, we present a deep learning method for deconvolution that, in lieu of end-to-end training with ground truths, is trained using known physics of the imaging system. Specifically, we train a generative adversarial network with images generated with the known point-spread function of the system, and combine this with unpaired experimental data that preserves perceptual content. Our method rapidly and robustly deconvolves and superresolves microscopy images, demonstrating a two-fold improvement in image contrast to conventional deconvolution methods. In contrast to common end-to-end networks that often require 1,000–10,000s paired images, our method is experimentally unsupervised and can be trained solely on a few hundred regions of interest. We demonstrate its performance on light-sheet microscopy with propagation-invariant Airy beams, including in calibration beads, oocytes, preimplantation embryos, and excised brain tissue, as well as illustrate its utility for Bessel-beam LSM. This method aims to democratise learned methods for deconvolution, as it does not require data acquisition outwith the conventional imaging protocol.
The effect of discrete wavelengths of visible light on the developing murine embryo
Publisher: Springer Science and Business Media LLC
Date: 23-06-2022
DOI: 10.1007/S10815-022-02555-4
Abstract: A current focus of the IVF field is non-invasive imaging of the embryo to quantify developmental potential. Such approaches use varying wavelengths to gain maximum biological information. The impact of irradiating the developing embryo with discrete wavelengths of light is not fully understood. Here, we assess the impact of a range of wavelengths on the developing embryo. Murine preimplantation embryos were exposed daily to wavelengths within the blue, green, yellow, and red spectral bands and compared to an unexposed control group. Development to blastocyst, DNA damage, and cell number/allocation to blastocyst cell lineages were assessed. For the longer wavelengths (yellow and red), pregnancy/fetal outcomes and the abundance of intracellular lipid were investigated. Significantly fewer embryos developed to the blastocyst stage when exposed to the yellow wavelength. Elevated DNA damage was observed within embryos exposed to blue, green, or red wavelengths. There was no effect on blastocyst cell number/lineage allocation for all wavelengths except red, where there was a significant decrease in total cell number. Pregnancy rate was significantly reduced when embryos were irradiated with the red wavelength. Weight at weaning was significantly higher when embryos were exposed to yellow or red wavelengths. Lipid abundance was significantly elevated following exposure to the yellow wavelength. Our results demonstrate that the impact of light is wavelength-specific, with longer wavelengths also impacting the embryo. We also show that effects are energy-dependent. This data shows that damage is multifaceted and developmental rate alone may not fully reflect the impact of light exposure.
Rectifying transport of a mixture of Brownian particles on an asymmetric periodic optical potential
Publisher: SPIE
Date: 28-05-2004
DOI: 10.1117/12.533746
Optical trapping of three-dimensional structures using dynamic holograms
Publisher: Optica Publishing Group
Date: 29-12-2003
DOI: 10.1364/OE.11.003562
Abstract: We demonstrate the use of a spatial light modulator (SLM) to facilitate the trapping of particles in three-dimensional structures through time-sharing. This method allows particles to be held in complex, three-dimensional configurations using cycling of simple holograms. Importantly, we discuss limiting factors inherent in current phase only SLM design for applications in both optical tweezing and atom trapping.
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 coherence measurements of vortex light fields using optically manipulated micro-apertures
Publisher: SPIE
Date: 13-09-2007
DOI: 10.1117/12.734131
Experimentally unsupervised deconvolution for light-sheet microscopy with propagation-invariant beams
Publisher: Springer Science and Business Media LLC
Date: 02-11-2022
DOI: 10.1038/S41377-022-00975-6
Abstract: Deconvolution is a challenging inverse problem, particularly in techniques that employ complex engineered point-spread functions, such as microscopy with propagation-invariant beams. Here, we present a deep-learning method for deconvolution that, in lieu of end-to-end training with ground truths, is trained using known physics of the imaging system. Specifically, we train a generative adversarial network with images generated with the known point-spread function of the system, and combine this with unpaired experimental data that preserve perceptual content. Our method rapidly and robustly deconvolves and super-resolves microscopy images, demonstrating a two-fold improvement in image contrast to conventional deconvolution methods. In contrast to common end-to-end networks that often require 1000–10,000s paired images, our method is experimentally unsupervised and can be trained solely on a few hundred regions of interest. We demonstrate its performance on light-sheet microscopy with propagation-invariant Airy beams in oocytes, preimplantation embryos and excised brain tissue, as well as illustrate its utility for Bessel-beam LSM. This method aims to democratise learned methods for deconvolution, as it does not require data acquisition outwith the conventional imaging protocol.
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.
Rapid imaging of mammalian brain slices with a compact light sheet fluorescent microscope
Publisher: SPIE
Date: 08-02-2017
DOI: 10.1117/12.2251227
Fibre-based imaging: new challenges
Publisher: SPIE
Date: 10-03-2015
DOI: 10.1117/12.2077693
Simultaneous micromanipulation in multiple planes using a self-reconstructing light beam
Publisher: Springer Science and Business Media LLC
Date: 09-2002
DOI: 10.1038/NATURE01007
Single cell transfection by laser-induced breakdown of an optically trapped gold nanoparticle
Publisher: SPIE
Date: 07-03-2014
DOI: 10.1117/12.2039647
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.
Optical trapping using ultrashort 12.9fs pulses
Publisher: SPIE
Date: 28-08-2008
DOI: 10.1117/12.795085
Optically trapped and controlled microapertures for studies of spatial coherence in an arbitrary light field
Publisher: AIP Publishing
Date: 25-06-2007
DOI: 10.1063/1.2751590
Abstract: By controlling the rotation rate of a trapped birefringent particle with an optically applied torque, the authors introduce a miniscule wave front deformation at a specific location within an arbitrary light field, with the particle acting as an optical microdiffuser. A trapped birefringent particle and a trapped silica microsphere are positioned to form Young’s double slit experiment within a probe light field. The far-field interference from the diffracted optical fields from these particles enable the authors to infer the relative spatial coherence between these local s ling points. With multiple trapped particles, the authors may perform multipoint coherence analysis of a light field.
Optical micromanipulation takes hold
Publisher: Elsevier BV
Date: 02-2006
Dielectric enhanced nanoparticles for three-dimensional optical manipulation
Publisher: SPIE
Date: 20-08-2009
DOI: 10.1117/12.825456
Internal physiology of live krill revealed using new aquaria techniques and mixed optical microscopy and optical coherence tomography (OCT) imaging techniques
Publisher: Informa UK Limited
Date: 25-08-2015
Optical Separation of Cells on Potential Energy Landscapes: Enhancement With Dielectric Tagging
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2007
Spatially optimized gene transfection by laser-induced breakdown of optically trapped nanoparticles
Publisher: AIP Publishing
Date: 28-02-2011
DOI: 10.1063/1.3554415
Abstract: We demonstrate laser-induced breakdown of an optically trapped nanoparticle with a nanosecond laser pulse. Controllable cavitation within a microscope s le was achieved, generating shear stress to monolayers of live cells. This efficiently permeabilize their plasma membranes. We show that this technique is an excellent tool for plasmid-DNA transfection of cells with both reduced energy requirements and reduced cell lysis compared to previously reported approaches. Simultaneous multisite targeted nanosurgery of cells is also demonstrated using a spatial light modulator for parallelizing the technique.
Optical Trapping Takes Shape: The Use of Structured Light Fields
Publisher: Elsevier
Date: 2008
Probing Vibrational Strong Coupling of Molecules with Wavelength‐Modulated Raman Spectroscopy
Publisher: Wiley
Date: 27-11-2021
Abstract: Raman spectroscopy is a powerful technique that enables fingerprinting of materials, molecules, and chemical environments by probing vibrational resonances. In many applications, the desired Raman signals are masked by fluorescence, either from the molecular system being studied, or from adjacent metallic nanostructures. Here, it is shown that wavelength‐modulated Raman spectroscopy provides a powerful way to significantly reduce the strength of the fluorescence background, thereby allowing the desired Raman signals to be clearly recorded. This approach is made use of to explore Raman scattering in the context of vibrational strong coupling, an area that has thus far been problematic to visualise. Specifically, strong coupling between the vibrational modes in a polymer and two types of confined light field, the fundamental mode of a metal‐clad microcavity, and the surface‐plasmon modes of an adjacent thin metal film are looked at. While clear advantages in using the wavelength‐modulated Raman approach are found, these results on strong coupling are inconclusive, and highlight the need for more work in this exciting topic area.
Atom guiding along high order Laguerre–Gaussian light beams formed by spatial light modulation
Publisher: Informa UK Limited
Date: 10-03-2006
Investigation of refractive index dynamics during in vitro embryo development using off-axis digital holographic microscopy
Publisher: Optica Publishing Group
Date: 13-06-2023
DOI: 10.1364/BOE.492292
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.
Dielectric resonator: cavity-enhanced optical manipulation in the near field
Publisher: SPIE
Date: 31-08-2006
DOI: 10.1117/12.681988
Long distance beam propagation in colloidal suspensions: comparison between theory and experiment
Publisher: SPIE
Date: 28-08-2008
DOI: 10.1117/12.796243
Interference from multiple trapped colloids in an optical vortex beam
Publisher: Optica Publishing Group
Date: 2006
DOI: 10.1364/OE.14.007436
Abstract: Laguerre-Gaussian (LG) beams are important in optical micromanipulation. We show that optically trapped microparticles within a monochromatic LG beam may lead to the formation of unique intensity patterns in the far field due to multiple interference of the forward scattered light from each particle. Trapped colloids create far field interference that exhibits distinct spiral wave patterns that are directly correlated to the helicity of the LG beam. Using two trapped particles, we demonstrate the first microscopic version of a Young's slits type experiment and detect the azimuthal phase variation around the LG beam circumference. This novel technique may be implemented to study the relative phase and spatial coherence of two points in trapping light fields with arbitrary wavefronts.
Optical steering of high and low index microparticles by manipulating an off-axis optical vortex
Publisher: IOP Publishing
Date: 20-11-2004
The testing of antibodies raised against poultry red mite antigens in an in vitro feeding assay; preliminary screen for vaccine candidates
Publisher: Springer Science and Business Media LLC
Date: 29-01-2009
DOI: 10.1007/S10493-009-9243-5
Abstract: Dermanyssus gallinae (De Geer), the poultry red mite, is a blood-feeding ectoparasite that infests many bird species. We have used an in vitro feeding assay to allow the identification of protective D. gallinae antigens that may have potential as vaccine candidates. Homogenised mites were extracted sequentially with PBS, Tween 20, Triton X100 and urea giving four protein fractions. Five experimental groups of Lohmann Brown hens were used to generate antibodies four groups were injected with one of each of the protein fractions in QuilA adjuvant and a control group was injected with adjuvant only. Booster injections were administered 2 and 4 weeks after initial immunisation. Eggs were collected throughout the experiment and soluble IgY antibodies were extracted from a pool of egg yolks collected at week six post-injection. Western blots, performed using post vaccination antibodies from test and control groups, revealed a strong antibody response against a range of injected proteins. Fresh chicken blood, supplemented with antibodies raised against these protein fractions, was fed to mites in an in vitro feeding assay in order to determine whether the antibodies had an anti-mite effect. Although there was variability in the numbers of feeding mites, it was found that the strongest anti-mite effect was seen with the PBS protein fraction, which had a cumulative average mortality of 34.8% 14 days after feeding compared with 27.3% for the control group (P = 0.043).
Laser-induced breakdown of an optically trapped gold nanoparticle for single cell transfection
Publisher: The Optical Society
Date: 28-08-2013
DOI: 10.1364/OL.38.003402
Does artificial intelligence have a role in the IVF clinic?
Publisher: Bioscientifica
Date: 15-09-2021
DOI: 10.1530/RAF-21-0043
Abstract: The success of IVF has remained stagnant for a decade. The focus of a great deal of research is to improve on the current ~30% success rate of IVF. Artificial intelligence (AI), or machines that mimic human intelligence, has been gaining traction for its potential to improve outcomes in medicine, such as cancer diagnosis from medical images. In this commentary, we discuss whether AI has the potential to improve fertility outcomes in the IVF clinic. Based on existing research, we examine the potential of adopting AI within multiple facets of an IVF cycle, including egg/sperm and embryo selection, as well as formulation of an IVF treatment regimen. We discuss both the potential benefits and concerns of the patient and clinician in adopting AI in the clinic. We outline hurdles that need to be overcome prior to implementation. We conclude that AI has an important future in improving IVF success.
Determination of optical forces in the proximity of a nanoantenna
Publisher: SPIE
Date: 19-08-2010
DOI: 10.1117/12.861474
Optical forces near a nanoantenna
Publisher: SPIE-Intl Soc Optical Eng
Date: 02-2010
DOI: 10.1117/1.3332850
Optically bound microscopic particles in one dimension
Publisher: American Physical Society (APS)
Date: 25-02-2004
Extended organization of colloidal microparticles by surface plasmon polariton excitation
Publisher: American Physical Society (APS)
Date: 21-02-2006
Numerical investigation of passive optical sorting of plasmon nanoparticles
Publisher: The Optical Society
Date: 06-07-2011
DOI: 10.1364/OE.19.013922
Correction to: Vitrification within a nanoliter volume: oocyte and embryo cryopreservation within a 3D photopolymerized device
Publisher: Springer Science and Business Media LLC
Date: 07-09-2022
Transient response of a cold atomic beam in the presence of a far-off resonance light guide
Publisher: Informa UK Limited
Date: 07-2003
Fabrication on the microscale: a two-photon polymerized device for oocyte microinjection
Publisher: Springer Science and Business Media LLC
Date: 12-05-2022
DOI: 10.1007/S10815-022-02485-1
Abstract: Intracytoplasmic sperm injection (ICSI) addresses male sub-fertility by injecting a spermatozoon into the oocyte. This challenging procedure requires the use of dual micromanipulators, with success influenced by inter-operator expertise. We hypothesized that minimizing oocyte handling during ICSI will simplify the procedure. To address this, we designed and fabricated a micrometer scale device that houses the oocyte and requires only one micromanipulator for microinjection. The device consisted of 2 components, each of sub-cubic millimeter volume: a Pod and a Garage. These were fabricated using 2-photon polymerization. Toxicity was evaluated by culturing single-mouse presumptive zygotes (PZs) to the blastocyst stage within a Pod, with several Pods (and embryos) docked in a Garage. The development was compared to standard culture. The level of DNA damage/repair in resultant blastocysts was quantified (γH2A.X immunohistochemistry). To demonstrate the capability to carry out ICSI within the device, PZs were microinjected with 4-μm fluorescent microspheres and cultured to the blastocyst stage. Finally, the device was assessed for oocyte traceability and high-throughput microinjection capabilities and compared to standard microinjection practice using key parameters (pipette setup, holding then injecting oocytes). Compared to standard culture, embryo culture within Pods and a Garage showed no differences in development to the blastocyst stage or levels of DNA damage in resultant blastocysts. Furthermore, microinjection within our device removes the need for a holding pipette, improves traceability, and facilitates high-throughput microinjection. This novel device could improve embryo production following ICSI by simplifying the procedure and thus decreasing inter-operator variability.
GPU accelerated toolbox for real-time beam-shaping in multimode fibres
Publisher: The Optical Society
Date: 31-01-2014
DOI: 10.1364/OE.22.002933
Optical nonlinearity of liquid nanosuspensions: Kerr versus exponential model
Publisher: SPIE
Date: 20-08-2009
DOI: 10.1117/12.825865
Aerosol tweezing with a super-continuum laser beam
Publisher: SPIE
Date: 28-08-2008
DOI: 10.1117/12.793726
Near-field optical manipulation with cavity enhanced evanescent fields
Publisher: SPIE
Date: 09-02-2006
DOI: 10.1117/12.660814
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.
Light-induced separation and flow of microscopic and biological particles
Publisher: SPIE
Date: 14-03-2005
DOI: 10.1117/12.606336
Observation of the Transfer of the Local Angular Momentum Density of a Multiringed Light Beam to an Optically Trapped Particle
Publisher: American Physical Society (APS)
Date: 29-08-2003
Applications of spatial light modulators in atom optics
Publisher: Optica Publishing Group
Date: 27-01-2003
DOI: 10.1364/OE.11.000158
Abstract: We discuss the application of spatial light modulators (SLMs) to the field of atom optics. We show that SLMs may be used to generate a wide variety of optical potentials that are useful for the guiding and dipole trapping of atoms. This functionality is demonstrated by the production of a number of different light potentials using a single SLM device. These include Mach-Zender interferometer patterns and the generation of a bottle-beam. We also discuss the current limitations in SLM technology with regard to the generation of both static and dynamically deformed potentials and their use in atom optics.
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.
In-fiber common-path optical coherence tomography using a conical-tip fiber
Publisher: Optica Publishing Group
Date: 05-02-2009
DOI: 10.1364/OE.17.002375
Abstract: Common-path optical coherence tomography (CPOCT) is known to reduce group velocity dispersion and polarization mismatch between the reference and the s le arm as both arms share the same physical path. Existing implementations of CPOCT typically require one to incorporate an additional cover glass within the beam path of the s le arm to provide a reference signal. In this paper, we aim to further reduce this step by directly making use of the back-reflected signal, arising from a conical lens-tip fiber, as a reference signal. The conical lens, which is directly manufactured onto the optical fiber tip via a simple selective-chemical etching process, fulfils two functions acting as both the imaging lens and the self-aligning reference plane. We use a Fourier-domain OCT system to demonstrate the feasibility of this technique upon biological tissue. An in-fiber CPOCT technique may prove potentially useful in endoscopic OCT imaging.
Optimal compressive multiphoton imaging at depth using single-pixel detection
Publisher: The Optical Society
Date: 10-10-2019
DOI: 10.1364/OL.44.004981
Direct detection of optical phase conjugation in a colloidal medium
Publisher: Optica Publishing Group
Date: 2007
DOI: 10.1364/OE.15.006330
Abstract: Degenerate four-wave mixing is demonstrated using an artificial Kerr medium and is evidenced by directly observing the phase conjugation of a vortex signal beam. The nonlinear susceptibility is produced by a refractive index grating created in a suspension of dielectric microscopic particles optically confined in the intensity grating distribution of two interfering laser beams.
Nonlinear optical dynamics in nonideal gases of interacting colloidal nanoparticles
Publisher: American Physical Society (APS)
Date: 03-11-2009
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.
Passive optical sorting of plasmon nanoparticles: Numerical investigation of optimal illumination
Publisher: AIP
Date: 2011
DOI: 10.1063/1.3644220
Experimental observation of optical vortex evolution in a Gaussian beam with an embedded fractional phase step
Publisher: Elsevier BV
Date: 09-2004
Vitrification within a nanoliter volume: oocyte and embryo cryopreservation within a 3D photopolymerized device
Publisher: Springer Science and Business Media LLC
Date: 11-08-2022
DOI: 10.1007/S10815-022-02589-8
Abstract: Vitrification permits long-term banking of oocytes and embryos. It is a technically challenging procedure requiring direct handling and movement of cells between potentially cytotoxic cryoprotectant solutions. Variation in adherence to timing, and ability to trace cells during the procedure, affects survival post-warming. We hypothesized that minimizing direct handling will simplify the procedure and improve traceability. To address this, we present a novel photopolymerized device that houses the s le during vitrification. The fabricated device consisted of two components: the Pod and Garage . Single mouse oocytes or embryos were housed in a Pod, with multiple Pods docked into a Garage. The suitability of the device for cryogenic application was assessed by repeated vitrification and warming cycles. Oocytes or early blastocyst-stage embryos were vitrified either using standard practice or within Pods and a Garage and compared to non-vitrified control groups. Post-warming, we assessed survival rate, oocyte developmental potential (fertilization and subsequent development) and metabolism (autofluorescence). Vitrification within the device occurred within ~ 3 nL of cryoprotectant: this volume being ~ 1000-fold lower than standard vitrification. Compared to standard practice, vitrification and warming within our device showed no differences in viability, developmental competency, or metabolism for oocytes and embryos. The device housed the s le during processing, which improved traceability and minimized handling. Interestingly, vitrification-warming itself, altered oocyte and embryo metabolism. The Pod and Garage system minimized the volume of cryoprotectant at vitrification—by ~ 1000-fold—improved traceability and reduced direct handling of the s le. This is a major step in simplifying the procedure.
Direct electron-beam writing of continuous spiral phase plates in negative resist with high power efficiency for optical manipulation
Publisher: AIP Publishing
Date: 06-12-2004
DOI: 10.1063/1.1830678
Abstract: Laser beams propagating in Laguerre-Gaussian (LG) modes are of considerable interest due to their widespread applications in the areas of optical manipulation of microparticles, quantum entanglement of photons, nonlinear optics, optical vortex interactions, and atomic studies. However, the proliferation of LG beams has been h ered due to the absence of reliable and reproducible fabrication technologies in producing the required optical elements for their generation. In this letter, we describe a simple, reliable, and reproducible fabrication technique for a micron-sized spiral phase plate with high power efficiency (80%–90%) and good beam uniformity. This facilitates the widespread use of LG beams in various applications: as an ex le the fabricated elements can easily and readily be incorporated into an existing optical trapping system with minimum modification.
Snapshot hyperspectral imaging of intracellular lasers
Publisher: Optica Publishing Group
Date: 20-09-2023
DOI: 10.1364/OE.498022
Widefield light sheet microscopy using an Airy beam combined with deep-learning super-resolution
Publisher: Cold Spring Harbor Laboratory
Date: 27-02-2020
Transverse particle dynamics in a Bessel beam
Publisher: Optica Publishing Group
Date: 09-10-2007
DOI: 10.1364/OE.15.013972
Abstract: Spatially periodic optical fields can be used to sort dielectric microscopic particles as a function of size, shape or refractive index. In this paper we elucidate through both theory and experiment the behavior of silica microspheres moving under the influence of the periodic optical field provided by a Bessel beam. We compare two different computational models, one based on Mie scattering, the other on geometrical ray optics and find good qualitative agreement, with both models predicting the existence of distinct size-dependent phases of particle behavior. We verify these predictions by providing experimental observations of the in idual behavioral phases.
Bidirectional Optical Sorting of Gold Nanoparticles
Publisher: American Chemical Society (ACS)
Date: 02-04-2012
DOI: 10.1021/NL204378R
Abstract: We present a generic technique allowing size-based all-optical sorting of gold nanoparticles. Optical forces acting on metallic nanoparticles are substantially enhanced when they are illuminated at a wavelength near the plasmon resonance, as determined by the particle's geometry. Exploiting these resonances, we realize sorting in a system of two counter-propagating evanescent waves, each at different wavelengths that selectively guide nanoparticles of different sizes in opposite directions. We validate this concept by demonstrating bidirectional sorting of gold nanoparticles of either 150 or 130 nm in diameter from those of 100 nm in diameter within a mixture.
Related Organisations
No related organisations have been discovered for Kishan Dholakia.
Related Funding Activities
Australian Laureate Fellowships - Grant ID: FL210100099
Start Date: 05-2022
End Date: 04-2027
Amount: $3,401,828.00
Funder: Australian Research Council
View Funded ActivityDiscovery Projects - Grant ID: DP220102303
Start Date: 10-2022
End Date: 09-2025
Amount: $470,000.00
Funder: Australian Research Council
View Funded ActivityLinkage Infrastructure, Equipment And Facilities - Grant ID: LE230100005
Start Date: 2023
End Date: 12-2023
Amount: $852,787.00
Funder: Australian Research Council
View Funded ActivityARC Centres Of Excellence - Grant ID: CE230100006
Start Date: 2023
End Date: 12-2029
Amount: $34,948,820.00
Funder: Australian Research Council
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