A5034573452- Laser-induced spectroscopy and plasma
- Laser Material Processing Techniques
- Laser-Ablation Synthesis of Nanoparticles
- Laser-Plasma Interactions and Diagnostics
- Diamond and Carbon-based Materials Research
- Nonlinear Optical Materials Studies
- Surface Roughness and Optical Measurements
- ZnO doping and properties
- Laser Design and Applications
- Semiconductor Lasers and Optical Devices
- Ion-surface interactions and analysis
- High-pressure geophysics and materials
- Photonic Crystals and Applications
- Advanced Surface Polishing Techniques
- Solid State Laser Technologies
- Optical Coatings and Gratings
- Photonic and Optical Devices
- Laser-Matter Interactions and Applications
- Ga2O3 and related materials
- Orbital Angular Momentum in Optics
- Photorefractive and Nonlinear Optics
- Glass properties and applications
- Nanofabrication and Lithography Techniques
- nanoparticles nucleation surface interactions
- Silicon Nanostructures and Photoluminescence
Waseda University
2023-2024
Osaka University
2014-2023
Institute for Laser Technology
2008-2022
Science Research Laboratory
2016
National Institute of Technology, Kagawa College
2012
Tohoku University
2006-2009
Kyushu University
1999-2008
Japan Society
2007
The Japan Society of Applied Physics
2007
Fujitsu (Japan)
1993
The quest for the inertial confinement fusion (ICF) ignition is a grand challenge, as exemplified by extraordinary large laser facilities. Fast isochoric heating of pre-compressed plasma core with high-intensity short-pulse an attractive and alternative approach to create ultra-high-energy-density states like those found in ICF sparks. This avoids quench caused hot spark mixing surrounding cold fuel, which crucial problem currently pursued scheme. High-intensity lasers efficiently produce...
The generation of a nano-sized hollow bump array gold thin film by uniformly spaced melting and inflation the induced single shot four interfering fs laser beams is reported. shape changed from bump, to bead on standing hole, finally with increase in fluence. height, diameter, as functions fluence are shown. Moreover, basic upon changing number beams.
Nano-structured ZnO thin films were synthesized by the nanoparticle assisted pulsed-laser deposition in an oxygen background gas. Crystallized and c-axis oriented nanorods with a size of approximately 300 nm average diameter 6 µm length grown on sapphire substrates heated at 700°C technique without any catalyst. Strong photoluminescence near band-gap was observed from under excitation 308 nm. The Rayleigh scattering diagnostics plume also conducted, revealing that grew nanoparticles which...
A petawatt laser for fast ignition experiments (LFEX) system [N. Miyanaga et al., J. Phys. IV France 133, 81 (2006)], which is currently capable of delivering 2 kJ in a 1.5 ps pulse using 4 beams, has been constructed beside the GEKKO-XII facility demonstrating efficient heating dense plasma up to temperature under auspices Fast Ignition Realization EXperiment (FIREX) project [H. Azechi Nucl. Fusion 49, 104024 (2009)]. In FIREX experiment, cone attached spherical target containing fuel...
Recently, several petawatt (PW, 1015 W) lasers with pulse duration of ∼20–30 fs have been introduced throughout the world, pushing upper limit on laser peak power. However, besides well-known spatio-temporal coupling effects, such as residual spatial/angular chirps and pulsefront tilt/curvature, spatio-temporal/spectral in compressors induced by wavefront errors gratings, which could dramatically distort ultra-intense pulses, has neglected. In this work, for first time we analyzed phenomenon...
A line of periodic dot structure with an interval 6.25 μm on a gold thin film was fabricated single shot interfered femtosecond laser beams split by diffraction beam splitter. The total length the 6 mm. In addition, matrix and comb structures were transportation samples at arbitrary speed during process. worked as transmission reflection gratings. nanowires peeling structure, which thickness 200 nm.
Based on the successful result of fast heating a shell target with cone for beam injection at Osaka University in 2002 using PW laser (Kodama et al Nature 418 933), FIREX-1 project was started 2004. Its goal is to demonstrate fuel up 5 keV an upgraded beam. For this purpose, LFEX laser, which can deliver energy to10 kJ 0.5–20 ps pulse its full spec, has been constructed addition Gekko-XII system Institute Laser Engineering, University. It activated and became operational since 2009....
Fast isochoric laser heating is a scheme to heat matter with relativistic intensity ($>{10}^{18}\text{ }\text{ }\mathrm{W}/{\mathrm{cm}}^{2}$) pulse for producing an ultrahigh-energy-density (UHED) state. We have demonstrated efficient fast of compressed dense plasma core multipicosecond kilojoule-class petawatt and assistance externally applied kilotesla magnetic fields guiding electrons the plasma. A UHED state 2.2 PPa achieved experimentally 4.6 kJ total energy that one order magnitude...
One-dimensional-imaging laser-induced fluorescence spectroscopy (1D-LIF) has been applied to investigate the dynamics of nonemissive neutral particles (YO molecules) during ArF excimer laser ablation YBa2Cu3O7−δ in an ambient oxygen gas. Investigating 1D-LIF observation, propagation through gas at appropriately high pressures is categorized into two phases, phase and diffusion phase. In phase, point source blast wave model (shock model) describes well background pressures. Particles...
The world's largest peta watt (PW) laser LFEX, which delivers energy up to 2 kJ in a 1.5 ps pulse, has been constructed beside the GEKKO XII at Institute of Laser Engineering, Osaka University. GEKKO-LFEX facility enables creation materials having high-energy-density do not exist naturally on Earth and have an density comparable that stars. High-energy-density plasma is source safe, secure, environmentally sustainable fusion energy. Direct-drive fast-ignition intensively studied this under...
Laser pulse contrast exceeding 1011 was demonstrated on a kilojoule-class petawatt laser for fast ignition experiments (LFEX) system [J. Phys. IV France133, 81 (2006)10.1051/jp4:2006133016] by implementing 2 in. plasma mirror. beams of up to 1.2 kJ striking the mirror with duration 1.5 ps were reflected and focused onto target without significant distortions in focal spot. Transmitted light from reveals that it has high reflectivity before main peak. The estimated at 1 ns No preformed...
The fluorescence characteristics of different Ce3+:Er3+-codoped fluoride host glasses, such as fluorozirconate and fluoroindate glass, are reported. It is shown that Ce3+ codoping into Er3+ doped glasses resulted in a quenching ions from the I11/24 to I13/24 state, branching ratio for I11/24→I13/24 transition increased 0.20 over 0.80 by 2.0 mol % Ce3+. Further, quantum yield at 1.55 μm was also significantly improved. A fiber laser operating band with 980 nm excitation has been realized...
Particle dynamics during Si nanoparticle synthesis in a laser-ablation plume different background gases were investigated by laser-spectroscopic imaging techniques. Two-dimensional laser induced fluorescence and ultraviolet Rayleigh scattering techniques used to visualize the spatial distribution of atoms nanoparticles grown, respectively. We have developed visualization technique called re-decomposition laser-induced observe small (hereafter clusters) which are difficult conventional In...
Two-dimensional time-resolved density distributions of ground state barium (Ba) and copper (Cu) atoms as well yttrium oxide (YO) molecules have been measured by two-dimensional laser-induced fluorescence during a pulsed-laser deposition (PLD) process YBa2Cu3O7−x. The gas phase PLD has investigated at ambient oxygen pressures between vacuum 1 Torr. Characteristic behaviors observed for each the species. This is due to different oxidation schemes with gas. Whereas YO mainly formed near...
Abstract Laser-induced forward transfer (LIFT) is a direct-writing technique capable of depositing single dot smaller than the laser wavelength at small shot energy through laser-induced (LIDT) technique. To deposit nanodot in irradiation, liquid nanodrop transferred from donor to receiver and finally solidified via solid–liquid–solid (SLS) process. In conventional LIDT experiments, multi-shots with step scanning have been used form array structures. However, interference processing can...