A5035647702- Laser Material Processing Techniques
- Laser-induced spectroscopy and plasma
- Phase-change materials and chalcogenides
- Photonic and Optical Devices
- Diamond and Carbon-based Materials Research
- Orbital Angular Momentum in Optics
- Laser-Matter Interactions and Applications
- Laser-Ablation Synthesis of Nanoparticles
- Laser-Plasma Interactions and Diagnostics
- Advanced X-ray Imaging Techniques
- Nonlinear Optical Materials Studies
- Laser Design and Applications
- Advanced Fiber Laser Technologies
- Ocular and Laser Science Research
- Atomic and Molecular Physics
- Chalcogenide Semiconductor Thin Films
- Photorefractive and Nonlinear Optics
- X-ray Spectroscopy and Fluorescence Analysis
- High-pressure geophysics and materials
- Plant tissue culture and regeneration
- Carbon Nanotubes in Composites
- Photonic Crystals and Applications
- Microfluidic and Bio-sensing Technologies
- Glass properties and applications
- Advanced Electron Microscopy Techniques and Applications
Australian National University
2016-2025
Quantum (Australia)
2022-2023
Centre for Quantum Computation and Communication Technology
2022-2023
The University of Sydney
2007-2023
The University of Queensland
2023
Universidad Politécnica de Madrid
2022
Tokyo University of Agriculture and Technology
2022
Bern University of Applied Sciences
2022
United States Naval Research Laboratory
2022
Center for Physical Sciences and Technology
2022
The mechanism of ablation solids by intense femtosecond laser pulses is described in an explicit analytical form. It shown that at high intensities when the ionization target material complete before end pulse, same for both metals and dielectrics. physics this new regime involves ion acceleration electrostatic field caused charge separation created energetic electrons escaping from target. formulas thresholds rates dielectrics, combining parameters, are derived compared to experimental...
We demonstrate a new principle of optical trapping and manipulation increasing more than 1000 times the distance by harnessing strong thermal forces while suppressing their stochastic nature with vortex beams. Our approach expands particles into gas media provides full control over trapped particles, including transport pinpoint positioning ∼100 μm objects meter-scale ±10 accuracy.
We utilize the interaction of tightly focused ultrashort pulses with transparent media to imprint their local polarization in focal region. In particular, we demonstrate that this technique allows for a subwavelength resolution diagnostic complex states including presence longitudinal component electric field. Moreover, first ever material ablation field femtosecond pulses.
We report production of nanostructured carbon foam by a high-repetition-rate, high-power laser ablation glassy in Ar atmosphere. A combination characterization techniques revealed that the system contains both sp2 and sp3 bonded atoms. The material is novel form which graphite-like sheets fill space at very low density due to strong hyperbolic curvature, as proposed for ?schwarzite?. exhibits ferromagnetic-like behaviour up 90 K, with narrow hysteresis curve high saturation magnetization....
We report on the fabrication and optical properties of etched highly nonlinear As(2)S(3) chalcogenide planar rib waveguides with lengths up to 22.5 cm losses as low 0.05 dB/cm at 1550 nm - lowest ever reported. demonstrate strong spectral broadening 1.2 ps pulses, in good agreement simulations, find that ratio nonlinearity dispersion linearizes pulse chirp, reducing oscillations caused by self-phase modulation alone. When combined a spectrally offset band-pass filter, this gives rise...
We introduce a novel approach for all-optical trapping and manipulation of absorbing aerosol particles based on photophoretic force. demonstrate experimentally, in open air, the robust three-dimensional guiding agglomerates carbon nanoparticles with size spanned two orders magnitude, from 100 nanometers to 10 microns, over distances few millimeters, as well their acceleration up velocities 1 cm/s simultaneous large number particles.
We propose a novel ultrafast pulsed laser deposition (PLD) technique, which eliminates the well-known problem of contamination films produced by PLD with particulates ejected from target. The method uses low energy, picosecond duration pulses delivered onto target at rates several tens MHz and thus differs conventional utilizes high nanosecond (≈10 Hz) repetition rates. In this article we present theoretical background justifying define optimal conditions for efficient evaporation given...
At extreme pressures and temperatures, such as those inside planets stars, common materials form new dense phases with compacted atomic arrangements unusual physical properties. The synthesis study of matter at above 100 GPa temperatures 104 K—warm matter—may reveal the functional details planet star interiors, may lead to extraordinary Many have been predicted theoretically that be realized once appropriate formation conditions are found. Here we report a superdense stable phase...
We develop a theoretical approach for describing the optical trapping and manipulation of carbon nanoclusters in air with dual-vortex trap, as realized recently experiment [V.Shvedov et al., Opt.Express 17, 5743 (2009)].We calculate both longitudinal transverse photophoretic forces acting on spherical absorbing particle, then compare our predictions experimental data.
Abstract Ordinary materials can transform into novel phases at extraordinary high pressure and temperature. The recently developed method of ultrashort laser-induced confined microexplosions initiates a non-equilibrium disordered plasma state. Ultra-high quenching rates overcome kinetic barriers to the formation new metastable phases, which are preserved in surrounding pristine crystal for subsequent exploitation. Here we demonstrate that silicon produce several end phases. Comparison with...
Water droplets on rough hydrophobic surfaces are known to exist in two states; one which the droplet is impaled surface asperities (Wenzel state) and other, a superhydrophobic state air remains trapped beneath (Cassie state). Here, we demonstrate that water can transit from Wenzel-to-Cassie even though former energetically favored. We find distinct states produced. One true Cassie state, whereas other exhibits superhydrophobicity absence of vapor phase being roughness. Furthermore,...
Abstract The emergence of high repetition-rate X-ray free-electron lasers (XFELs) powered by superconducting accelerator technology enables the measurement significantly more experimental data per day than was previously possible. European XFEL is expected to provide 27,000 pulses second, over two orders magnitude any other XFEL. increased pulse rate a key enabling factor for single-particle diffractive imaging, which relies on averaging weak diffraction signal from single biological...
We report the fabrication and characterization of rib chalcogenide waveguides produced by dry etching with CF4 O2. The high index contrast (Deltan ~1) show a minimum propagation loss 0.25 dB/cm. refractive nonlinearity 100 times silica in As2S3 allowed observation pi phase shift due to self-phase modulation an 8 ps duration 1573 nm pulse 5 cm long waveguide.
We report the first demonstration of error-free 640 Gbit/s demultiplexing using Kerr non-linearity an only 5 cm long chalcogenide glass waveguide chip. Our approach exploits four-wave mixing by instantaneous nonlinear response chalcogenide. Excellent performance is achieved with 2 dB average power penalty and no indication error-floor. Characterisation FWM efficiency for given confirms good device.
We present experimental results on post-tuning the dispersion of a two-dimensional photonic crystal waveguide made from Ge 33 As 12 Se 55 chalcogenide glass by exploiting material photosensitivity to nearbandgap light.The change in refractive index and volume response exposure 633nm light resulted shift more than 5nm resonant coupling wavelength between tapered optical fiber modes W1 waveguide.This represents first proof principle demonstration photosensitive planar device.
We demonstrate that micron-sized light-absorbing particles can be trapped and transported photophoretically in air using an optical bottle formed inside the focal volume of a lens with controlled amount spherical aberration. This fiber-based single beam trap used numerous applications where true 3D manipulation delivery airborne micro-objects is required.
We suggest a new approach for selective trapping of light absorbing particles in gases by multiple optical bottle-beam-like traps created volume speckle field. demonstrate stable simultaneous confinement few thousand micro-particles air with single lowpower laser beam. The size distribution trapped exhibits narrow peak near the average an speckle. Thus, speckleformed act as sieve holes selecting similar size.
We demonstrate experimentally that, in a tight focusing geometry, circularly polarized femtosecond laser vortex pulses ablate material differently depending on the handedness of light. This effect offers an additional degree freedom to control shape and size laser-machined structures subwavelength scale.
Ultrafast pulsed laser deposition is a novel technique for depositing particle-free, thin solid films using very high repetition rate lasers. The process involves evaporation of the target by low energy pulses focused to an optimum intensity eliminate particles from vapor. This results in with surface quality while increases overall rate. Here we report experimental demonstration creating ultrasmooth, thin, amorphous carbon Nd:YAG Both 10 kHz, 120 ns Q-switched laser, or 76 MHz 60 ps...
Subtle atomic motion in a Bi crystal excited by 35 fs-laser pulse has been recovered from the transient reflectivity of an optical probe measured with accuracy ${10}^{\ensuremath{-}5}$. Analysis shows that novel effect reported here---an initial negative drop reflectivity---relates to delicate coherent displacement atoms polarization force during pulse. We also show oscillations frequency coinciding cold are related phonons electron temperature gradient through electron-phonon coupling.