Browsing by Author "LUNNEY, JAMES"
Now showing items 1-20 of 24
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Compression and focussing a laser produced plasma using a plasma optical system
LUNNEY, JAMES (2012)Axi-symmetric compression and focusing of a low temperature laser produced copper plasma with an electrostatic plasma optical system was investigated for the first time. The degree of plasma concentration was quantified ... -
Conical diffraction and Bessel beam formation with a high optical quality biaxial crystal
DONEGAN, JOHN; LUNNEY, JAMES; RAKOVICH, YURY (2009)The manipulation of a Gaussian laser beam using conical diffraction in a high optical quality biaxial crystal of KGd(WO4)2 has been examined in detail with emphasis on the experimental techniques involved and intuitive ... -
Conical diffraction of a Gaussian beam with a two crystal cascade
LUNNEY, JAMES; DONEGAN, JOHN; BALLANTINE, KYLE; EASTHAM, PAUL; PHELAN, CIARAN (2012) -
Conical diffraction of linearly polarised light controls the angular position of a microscopic object
LUNNEY, JAMES; DONEGAN, JOHN; RAKOVICH, YURY; PHELAN, CIARAN; BALLANTINE, KYLE (2010)Conical diffraction of linearly polarised light in a biaxial crystal produces a beam with a crescent-shaped intensity profile. Rotation of the plane of polarisation produces the unique effect of spatially moving the ... -
The creation and annihilation of optical vortices using cascade conical diffraction
LUNNEY, JAMES; DONEGAN, JOHN; PHELAN, CIARAN; RAKOVICH, YURY; EASTHAM, PAUL (2011)Internal conical diffraction produces a superposition of orthogonally polarised zero- and first-order Bessel like beams from an incident circularly polarised Gaussian beam. For right-circularly polarised light, the first-order ... -
Dynamics of the plumes produced by ultrafast laser ablation of metals
LUNNEY, JAMES; DONNELLY, TONY; DONNELLY, TONY (2010)We have analyzed ultrafast laser ablation of a metallic target (Nickel) in high vacuum addressing both expansion dynamics of the various plume components (ionic and nanoparticle) and basic properties of the ultrafast laser ... -
Dynamics of ZnO laser produced plasma in high pressure argon
LUNNEY, JAMES (2011)Pulsed laser deposition of ZnO in high pressure gas offers a route for the catalyst-free preparation of ZnO nanorods less than 10 nm in diameter. This paper describes the results of some experiments to investigate the laser ... -
Femtosecond ultraviolet laser ablation of silver and comparison with nanosecond ablation
LUNNEY, JAMES (2013)The ablation plume dynamics arising from ablation of silver with a 500 fs, 248nm laser at 2Jcm 2 has been studied using angle-resolved Langmuir ion probe and thin film deposition techniques. For the same laser fluence, ... -
Generation of a radially polarized light beam using internal conical diffraction
DONEGAN, JOHN; LUNNEY, JAMES; PHELAN, CIARAN (2011)Using a combination of internal conical diffraction and Mach-Zehnder interferometry we have theoretically and experimentally demonstrated an efficient new technique for the conversion of a linearly polarized Gaussian laser ... -
Generation of continuously tunable fractional optical orbital angular momentum using internal conical diffraction
DONEGAN, JOHN; PHELAN, CIARAN; LUNNEY, JAMES; RAKOVICH, YURY (2010)When a left-circularly polarised Gaussian light beam, which has spin angular momentum (SAM) J sp = ? ? = 1 ? per photon, is incident along one of the optic axes of a slab of biaxial crystal it undergoes internal ... -
Generation of continuously tuneable fractional optical orbital angular momentum using internal conical diffraction
LUNNEY, JAMES; RAKOVICH, YURY; EASTHAM, PAUL; DONEGAN, JOHN (2010)Abstract: When a left-circularly polarised Gaussian light beam, which has spin angular momentum (SAM) Jsp = ?? = 1? per photon, is incident along one of the optic axes of a slab of biaxial crystal it undergoes internal ... -
Heating and compression of a laser produced plasma in a pulsed magnetic field
LUNNEY, JAMES; DONNELLY, TONY (2016)A pulsed 0.3 T magnetic field was used to heat and compress a low-temperature laser produced copper plasma. The magnetic field was generated using a planar 3-turn coil positioned 10 mm above the ablation spot. The plasma ... -
Interaction of surface plasmons with CdTe quantum dot excitons
DONEGAN, JOHN; RAKOVICH, YURY; BRADLEY, LOUISE; LUNNEY, JAMES (SPIE, 2005)A 5-fold enhancement in the luminescence of CdTe nanocrystal quantum dots (QDs) is observed when they are placed in proximity to a nanostructured Au film deposited by pulsed laser deposition technique. No enhancement is ... -
Investigation of the optical properties of MoS2 thin films using spectroscopic ellipsometry
DUESBERG, GEORG; LUNNEY, JAMES; MCEVOY, NIALL; YIM, CHANYOUNG (2014)Spectroscopic ellipsometry (SE) characterization of layered transition metal dichalcogenide (TMD) thin films grown by vapor phase sulfurization is reported. By developing an optical dispersion model, the extinction coefficient ... -
Laser triggered Z-pinch broadband extreme ultraviolet source for metrology
LUNNEY, JAMES (2013)We compare the extreme ultraviolet emission characteristics of tin and galinstan (atomic %: Ga: 78.35, In: 14.93, Sn: 6.72) between 10 nm and 18 nm in a laser-triggered discharge between liquid metal-coated electrodes. ... -
Multidiagnostic analysis of ultrafast laser ablation of metals with pulse pair
LUNNEY, JAMES (2010)Copper targets are irradiated in the ablation regime by pairs of equal, time-delayed collinear laser pulses separated on a timescale going from 2 ps to 2 ns. The ablation plume is characterized by ion probe diagnostic, ... -
Observation of a new interference phenomena in internal conical diffraction
DONEGAN, JOHN; LUNNEY, JAMES (2015)Conical diffraction is observed in biaxial materials when a beam of light is directed along one of the two optic axis directions. When the beam is directed close to but not along an optic axis, a rich interference pattern ... -
Optical trapping using cascade conical refraction of light
DONEGAN, JOHN; BALLANTINE, KYLE; PHELAN, CIARAN; LUNNEY, JAMES (2012) -
Oxidation of ZnO thin films during pulsed laser deposition process
LUNNEY, JAMES (2013)Pulsed laser deposition of ZnO thin films, using KrF laser, is analysed. The films were deposited on (001) sapphire substrates at 400 °C, at two different oxygen pressures (0·3 and 0·4 mbar) and two different target–substrate ...