A5033471739- Solid State Laser Technologies
- Laser Design and Applications
- Advanced Fiber Laser Technologies
- Spectroscopy and Laser Applications
- Laser Material Processing Techniques
- Laser-Matter Interactions and Applications
- Semiconductor Lasers and Optical Devices
- Stellar, planetary, and galactic studies
- Photorefractive and Nonlinear Optics
- Astronomy and Astrophysical Research
- Laser-induced spectroscopy and plasma
- Photonic and Optical Devices
- Adaptive optics and wavefront sensing
- Photonic Crystals and Applications
- Photonic Crystal and Fiber Optics
- Plasmonic and Surface Plasmon Research
- Ocular and Laser Science Research
- Random lasers and scattering media
- Advanced Fiber Optic Sensors
- Optical Coherence Tomography Applications
- Luminescence Properties of Advanced Materials
- Diamond and Carbon-based Materials Research
- Atomic and Subatomic Physics Research
- Astronomical Observations and Instrumentation
- Orbital Angular Momentum in Optics
Macquarie University
2012-2021
Karlsruhe Institute of Technology
2020
Centre for Ultrahigh Bandwidth Devices for Optical Systems
2013-2017
University North
2009
University of Oxford
1996-2006
Oxford Lasers (United Kingdom)
1998-2003
University of Cambridge
2002
Science Oxford
2000-2001
Japan External Trade Organization
2001
We present a highly efficient picosecond diamond Raman laser synchronously-pumped by 4.8 W mode-locked at 1064 nm. A ring cavity was adopted for operation. With low-Q first-Stokes 1240 nm, we have achieved 2.75 output power nm with 59% overall conversion efficiency. The slope efficiency tended towards 76% far above the SRS threshold, approaching quantum limit diamond. high-Q employed second-Stokes 1485 generation through combined processes of four-wave mixing and single-pass stimulated...
In the 30 years since tunable ultraviolet (UV) lasers based on 5d /spl rarr/ 4f transition of trivalent lanthanides doped into solid-state hosts were first demonstrated, tremendous progress has been made in these unique laser systems. Today, cerium-doped fluoride offer wide tunability (280-333 nm), high efficiency (up to 62%) and narrow-band output. These can also be used for femtosecond pulse amplification UV. Cerium represent a logical route generation UV all-solid-state this paper, we...
We report a parametric anti-Stokes Raman laser using potassium gadolinium tungstate, generating output chiefly at the first 508 nm. The compact 4.5 cm long device is pumped by Q-switched 532 nm and uses an off-axis Stokes resonator to provide non-collinear phase matching between pump generated fields. Anti-Stokes energies up 0.27 mJ were obtained conversion efficiency from of 0.46%. Second- third-order lines 486 465 also observed.
We investigated the spectral and coherence signatures of threshold in random lasers with incoherent feedback consisting alumina colloidal nanoparticles suspended rhodamine 6G methanol solution under nanosecond-pulsewidth pumping, based on measurement temporal spatial properties comparison emission spectra. Feedback this laser was provided by multiple scattering from particles, effects particle concentration length were studied for weakly diffusive regimes. At threshold, each regime,...
The Keck Planet Finder (KPF) is a fiber-fed, high-resolution, high-stability spectrometer in development for the W.M. Observatory. instrument recently passed its preliminary design review and currently detailed phase. KPF designed to characterize exoplanets using Doppler spectroscopy with single measurement precision of 0.5 m s<sup>−1</sup> or better; however, resolution stability will enable wide variety other astrophysical pursuits. have 200 mm collimated beam diameter resolving power...
In this paper, a compact master-oscillator power-amplifier laser system incorporating telescopic beam expansion in high-gain double-pass amplifier is presented. A miniature (0.5 W) copper vapor used to efficiently extract over 37 W of high-beam-quality (full transverse coherence) output power from kinetically enhanced nominally 35-W at 12-kHz pulse repetition frequency. By configuring the oscillator for low coherence and using multimode optical fiber between amplifier, high-power (34...
We report mode-locked operation of a synchronously pumped Ce:LiCAF oscillator. The laser operated in the deep UV with output radiation centered at 291 nm and pulse duration 6 ps. maximum power measured was 52 mW, 13% slope efficiency. crystal has gain bandwidth capable supporting few-femtosecond pulses, so our results demonstrate potential to form new class ultrafast lasers operating directly wavelengths.
The RHEA Spectrograph is a single-mode echelle spectrograph designed to be replicable and cost effective method of undertaking precision radial velocity measurements. Two versions currently exist, one located at the Australian National University in Canberra, Australia (450 - 600nm wavelength range), another Subaru Telescope Hawaii, USA (600 800 nm range). Both instruments have novel fibre feed consisting an integral field unit injecting light into 2D grid single mode fibres. This fibres...
SCExAO is the premier high-contrast imaging platform for Subaru Telescope. It offers high Strehl ratios at near-IR wavelengths (y-K band) with stable pointing and coronagraphs extremely small inner working angles, optimized faint companions very close to host. In visible, it has several interferometric imagers which offer polarimetric spectroscopic capabilities. A recent addition RHEA spectrograph enabling spatially resolved resolution spectroscopy of surfaces giant stars, example. New...
Ultraviolet (UV) powers of over 1 W have been obtained by second harmonic and sum frequency generation from a single medium scale (20 W) copper vapor laser (CVL) using new focal geometry in which the CVL beam is focused only one direction to produce line focus within BBO crystal. High optical conversion efficiencies, 20 30%, are observed for low divergence ( approximately -10 times diffraction limit) diffraction-limited components output, respectively. Wall-plug efficiencies UV up 0.04%....
The temporal evolution of the far-field intensity distribution (and hence beam divergence) for output a CVL operating with both on-axis and off-axis unstable resonators is investigated in detail. pulse consists several temporally resolved components, where each successive component has lower divergence approaching diffraction limit. A comprehensive model from variety presented. In this resonator controls by imposing geometric constraints on propagation spontaneous emission repeated...
Detailed parametric investigations of line foci for efficient nonlinear frequency conversion copper-vapor lasers are presented. For a single medium-scale laser (nominally 20 W), the optimum focal geometry second-harmonic and sum-frequency generation in BBO is to focus 3.75-mm-diameter beam into crystal with an f=60 mm cylindrical lens, Using such geometry, UV powers up 1.75 W (SHG green), 1.2 yellow), 1.5 (SFG) have been produced peak instantaneous efficiency 48%. Conversion efficiencies...
We demonstrate chopped-cw lasing in a Ce:LiCAF oscillator directly generating deep-UV light around 290 nm. The cw output was achieved by asynchronous pumping of mode-locked frequency quadrupled Nd:YVO4 laser that generates 23 ps pulses 266 nm at repetition rate 80 MHz. pump chopped with 8.3% duty cycle to minimize thermal effects the quadrupling stage. maximum power 384 mW when pumped 3.3 W pulsed light, slope efficiency 33%. tunable from 286 295 potential be broadened over full gain...
Abstract Ever since the laser's invention, there has been great interest in increasing beam output power without detriment to its coherence. Despite advances having obtained through use of a diverse range approaches, steady‐state powers above ten kilowatts remain significant challenge for solid‐state lasers due heightened impact detrimental nonlinear effects such as thermal lensing. Multiplexing several using combination represents method surpassing barriers single lasers. Here we propose...
We present the opto-mechanical design and characterization of Replicable High-resolution Exoplanet Asteroseismology (RHEA) spectrograph. RHEA is an ultra-compact fiber-fed echelle spectrograph designed to be used at 0.2-0.4 m class robotic telescopes where long term dedicated projects are possible. The instrument will primarily for radial velocity (RV) studies low intermediate-mass giant stars purpose searching hot Jupiters using asteroseismology simultaneously measure host star parameters...
The Keck Planet Finder (KPF) is a fiber-fed, high-resolution, high-stability spectrometer in development at the UC Berkeley Space Sciences Laboratory for W.M. Observatory. KPF designed to characterize exoplanets via Doppler spectroscopy with goal of single measurement precision 0.3 m s<sup>-1</sup> or better, however its resolution and stability will enable wide variety astrophysical pursuits. Here we provide post-preliminary design review updates several subsystems, including: main...
Generation at 271 nm by frequency summing the two copper vapor laser (CVL) output wavelengths (at 511 and 578 nm) in beta -BBO KDP is reported. A maximum sum of 100 mW was obtained for 6.8 W total pump power from a CVL operating with fully unstable (M=16) confocal cavity.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Progress in high average power UV generation by nonlinear frequency conversion of the output copper-vapor lasers (CVL's) is reviewed. The specific parameters controlling efficiency using CVL's are highlighted, with CVL beam quality and matching optical delivery system to characteristics crystal being identified as most significant issues. Recent experimental studies second harmonic (SHG) single-CVL oscillators oscillator-amplifier systems show that careful optimization pump laser systems, it...
We report, for what we believe to be the first time, a Ce:LiCAF laser pumped by ultraviolet radiation obtained sum-frequency mixing of green and yellow output from copper-vapor laser. The 7-kHz pulse repetition frequency free-lasing yielded maximum power 530 mW, with slope efficiency 32%, pump 1.9 W. With single prism tunability 280.5 316 nm was achieved.
Continuous tunability of a 10 kHz PRF Ce:LiLuF4 laser is described. The untuned yielded up to 360 mW output power at wavelength 309 nm, with slope efficiency 51%. By means single prism, was achieved continuously from 305.0 333.2 nm.
We report on the laser action of pyrromethene 567 incorporated into polymeric matrices and pumped longitudinally with green line a copper-vapor laser. When dye was dissolved in copolymer methyl methacrylate pentaerythritol triacrylate, 290 mW average power at 1 kHz (37% lasing efficiency) obtained. The output decreased to 150 after 30 min irradiation time (1.8×106 shots) 32 70 operation (4.2×106 shots). Output up W 6.2 obtained for short periods time. Polymeric incorporating rhodamine 6G...