A5001551063- Laser Material Processing Techniques
- Ocular and Laser Science Research
- Laser-induced spectroscopy and plasma
- Nonlinear Optical Materials Studies
- Laser-Ablation Synthesis of Nanoparticles
- Advanced Surface Polishing Techniques
- TiO2 Photocatalysis and Solar Cells
- Silicon Nanostructures and Photoluminescence
- Graphene research and applications
- Gold and Silver Nanoparticles Synthesis and Applications
- Diamond and Carbon-based Materials Research
- Surface Roughness and Optical Measurements
- Adhesion, Friction, and Surface Interactions
- Metal and Thin Film Mechanics
- 2D Materials and Applications
- Electronic and Structural Properties of Oxides
- Solid State Laser Technologies
- Chalcogenide Semiconductor Thin Films
- Quantum Dots Synthesis And Properties
- Spectroscopy Techniques in Biomedical and Chemical Research
- Catalysis and Oxidation Reactions
- Transition Metal Oxide Nanomaterials
- nanoparticles nucleation surface interactions
- Thermography and Photoacoustic Techniques
- Glass properties and applications
Czech Academy of Sciences, Institute of Physics
2015-2025
Trinity College Dublin
2012-2018
Macquarie University
2007
University of Stuttgart
2007
The University of Melbourne
2007
Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation Chanyoung Yim, Maria O'Brien, Niall McEvoy, Sinéad Winters, Inam Mirza, James G. Lunney, Georg S. Duesberg; Investigation of the optical properties MoS2 thin films using spectroscopic ellipsometry. Appl. Phys. Lett. 10 March 2014; 104 (10): 103114. https://doi.org/10.1063/1.4868108 Download citation file: Ris...
Nanodiamond crystals containing single color centers have been grown by chemical vapor deposition (CVD). The fluorescence from individual crystallites was directly correlated with crystallite size using a combined atomic force and scanning confocal microscope. Under the conditions employed, optimal for optically active nitrogen-vacancy (NV) center incorporation measured to be 60−70 nm. findings highlight strong dependence of NV on crystal size, particularly less than 50 nm in size.
Abstract In this paper, we establish connections between the thresholds and mechanisms of damage white-light generation upon femtosecond laser irradiation wide-bandgap transparent materials. On example Corning Willow glass, evolution ablation craters, their quality, emission were studied experimentally for 130-fs, 800-nm pulses. The experimental results indicate co-existence several which can be separated in time. Suppression phase explosion mechanism was revealed at middle spots. At high...
Laser treatment of amorphous TiO<sub>2</sub>nanotube layers leads to their crystallization without deformation or formation the thermal oxide layer.
Pulsed laser ablation in liquids is one of the most versatile and widespread techniques for easy synthesis different types nanoparticles with controllable properties. A huge amount energy compressed into pulse that directed onto a solid target leads to ejection materials surrounding liquid. However, precision focus irradiation can play crucial role nanomaterials and, hence, significantly affect their physico-chemical In this paper, we investigated influence position spot on optical...
Nanoparticle (NP) films of silver were prepared using nanosecond (ns) and femtosecond (fs) pulsed laser deposition (PLD) in vacuum. The flux energy distribution the ions plasma part ablation plume measured a Langmuir ion probe. efficiencies ns fs PLD also compared. For equivalent thickness up to ∼3 nm NPs made by ns-PLD are well separated roughly circular, but for higher thicknesses begin coalesce. 7 comprised NPs, though mean NP size surface coverage increase with thickness. Feret diameter...
A systematic experimental study was performed to determine laser irradiation conditions for the large-area fabrication of highly regular laser-induced periodic surface structures (HR-LIPSS) on a 220 nm thick Mo film deposited fused silica. The LIPSS were fabricated by scanning linearly polarized, spatially Gaussian beam at 1030 wavelength and 1.4 ps pulse duration over sample 1 kHz repetition rate. Scanning electron microscope images produced analyzed using criterion dispersion orientation...
Ultrafast laser processing possesses unique outlooks for the synthesis of novel nanoarchitectures and their further applications in field life science. It allows not only formation multi-element nanostructures with tuneable performance but also provides various non-invasive laser-stimulated modalities. In this work, we employed ultrafast manufacturing silicon–gold nanocomposites (Si/Au NCs) Au mass fraction variable from 15% (0.5 min ablation time) to 79% (10 min) which increased plasmonic...
Interaction of ultrashort laser pulses with transparent materials is a powerful technique modification material properties for various technological applications. The physics behind laser-induced phenomenon rich and still far from complete understanding. We present an overview our models developed to describe processes induced by inside on the surface bulk glass. most sophisticated model consists two parts. first part solves Maxwell's equations supplemented rate hydrodynamics free electrons....
Transmission measurements for femtosecond laser pulses focused in air with spectral analysis of emission from the focal region have been carried out various pulse energies and pressures. The breakdown threshold attenuation due to plasma absorption are evaluated compared calculations based on multiphoton ionization model. is found depend repetition rate considerably stronger at 1 kHz than 1–10 Hz. This suggests that accumulation metastable states molecules plays an important role initiation...
Pulsed laser ablation is one of the most efficient and clean methods for high-precision processing modification polymers biomaterials. Polymer has been extensively investigated with ultraviolet lasers while little attention given to infrared (IR) region, which becomes particularly interesting recent advances in ultrashort technologies. Here, we report results a comparative study on 1030-nm structuring Kapton polyimide, polymer important variety applications, direct comparison 247-fs 7-ps...
Spot size measurements of a 260 fs, 1030 nm focused spatially Gaussian pulsed laser beam were performed on Silicon surface with native and thermally grown SiO2 layers using widely known method evaluating energy dependent damage area.Single pulse induced thresholds both samples also measured.Modification the layer was analyzed in detail optical, confocal scanning electron microscopy.Restrictions spot transparent coatings several observable are discussed.
As-prepared nanostructured semiconductor materials are usually found in an amorphous form, which needs to be converted into a crystalline one for improving electronic properties and achieving enhanced application functionalities. The most utilized method is thermal annealing furnace, however time- energy-consuming not applicable low-temperature melting substrates. An alternative laser annealing, can carried out relatively short time and, additionally, offers the possibility of localized...
The Z-scan technique, using femtosecond (fs) laser pulses at 1480 nm pulses, was used to measure the nonlinear optical properties of gold (Au) nanoparticle (NP) films made by both nanosecond (ns) and fs pulsed deposition (PLD) in vacuum. At irradiance levels 1×1012 Wm−2, ns-PLD displayed induced absorption with β=4×10−5 mW−1, a negative lensing effect n2=−4.7×10−11 m2 W−1 somewhat smaller values for fs-PLD films. These n2 imply an unphysically large change real part refractive index,...
With the goal of substituting a hard metallic material for soft Ultra High Molecular Weight Polyethylene (UHMWPE) presently used to make bases skis alpine skiing, we two non-thermodynamic equilibrium surface treatments with ultra-short (7–8 ps) laser pulses modify square plates (50 × 50 mm2) made austenitic stainless steel AISI 301H. By irradiating linearly polarized pulses, obtained Laser Induced Periodic Surface Structures (LIPSS). machining, produced engraving on surface. Both produce...
Silica optical fibers are employed in endoscopy and related minimally invasive medical methods thanks to their good transparency flexibility. Although silicon oxide is a biocompatible material, its use involves serious health risk due fragility the fact that potential fiber fragments can freely move inside body without possibility of being detected by conventional such as X-ray imaging. A possible solution this issue be development based on bioresorbable (i.e., biodegradable biocompatible)...
Surface irradiation of AISI 301 with ultra-short linearly polarized pulses between 247 fs and 7 ps resulted in laser induced periodic surface structures (LIPSS). Scanning electron microscope micrographs taken after the treatment show formation sub-micrometer sized arrays nearly parallel ripples slightly differing from each other, depending on specific adopted. Static contact angle data indicate that LIPSS induce a marked hydrophobic behavior treated surfaces. The friction coefficient...
A study of damage and ablation silicon induced by two individual femtosecond laser pulses different wavelengths, 1030 515 nm, is performed to address the physical mechanisms dual-wavelength reveal possibilities for increasing efficiency. The produced craters damaged areas are analyzed as a function time separation between compared with monochromatic same total energy. Particular attention given low-fluence irradiation regimes when energy densities in each pulse below threshold thus no...
A study of damage and ablation silicon induced by two individual femtosecond laser pulses different wavelengths, 1030 515 nm, is performed to address the physical mechanisms dual-wavelength reveal possibilities for increasing efficiency.The produced craters damaged areas are analyzed as a function time separation between compared with monochromatic same total energy.Particular attention given low-fluence irradiation regimes when energy densities in each pulse below threshold thus no...
Using different laser irradiation patterns to modify of silicon surface, it has been demonstrated that, at rather small overlapping between spots, highly regular laser-induced periodic surface structures (LIPSS) can be produced already starting from the second pulse, provided that polarization direction coincides with scanning direction. If spot is shifted previous one perpendicular light polarization, LIPSS are not formed even after many pulses. This coherence effect explained by a...
Abstract Using different laser irradiation patterns to modify silicon surface, it has been demonstrated that, at rather small overlapping between spots, highly regular laser-induced periodic surface structures (LIPSS) can be produced already starting from the second pulse, provided that polarization direction coincides with scanning direction. If spot is shifted previous one perpendicular light polarization, LIPSS are not formed even after many pulses. This coherence effect explained by a...