The Review of Laser Engineering
Online ISSN : 1349-6603
Print ISSN : 0387-0200
ISSN-L : 0387-0200
Volume 40 , Issue 2
Special Issue on Leading Edge of Laser Processing in Liquid
Showing 1-14 articles out of 14 articles from the selected issue
Special Issue on Leading Edge of Laser Processing in Liquid
Special Issue
Laser Review
  • Tsuyoshi ASAHI
    2012 Volume 40 Issue 2 Pages 76-
    Published: 2012
    Released: July 16, 2020
    JOURNALS FREE ACCESS
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  • Yoshihiro TAKEDA, Fumitaka MAFUNÉ
    2012 Volume 40 Issue 2 Pages 77-
    Published: 2012
    Released: July 16, 2020
    JOURNALS FREE ACCESS
    Nanometer sized particles can show size dependent physical and chemical properties. Hence, preparation of size-controlled metal nanoparticles in a solution is one of the important subjects in chemistry and physics of nano-scale materials. A considerable number of efforts have been directed for developing methods of their preparation such as chemical reduction of a metal salt in a micelle or a reversed micelle. On the analogy of the laser ablation for preparing gas-phase clusters, a laser ablation method for preparation of metal nanoparticles in a liquid has also been developed by many researchers. Recent development of laser ablation in a solution for the nanoparticle production is overviewed. Mechanism of nanoparticles formation, size-reduction and relevant physical processes are described.
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  • Naoto KOSHIZAKI, Alexander PYATENKO, Hongqiang WANG, Yoshie ISHIKAWA
    2012 Volume 40 Issue 2 Pages 83-
    Published: 2012
    Released: July 16, 2020
    JOURNALS FREE ACCESS
    We developed a new fabrication technique for submicrometer spherical particles by pulsed laser melting in liquid. In this technique, nanosecond pulsed laser irradiation at relatively low fl uence to nanoparticles dispersed in liquid induces particle melting to form droplets, resulting in spherical particle formation by quenching. This process produces submicrometer spherical particles of various materials, such as metals, oxides, and semiconductors. We demonstrated a few examples of spherical particle fabrication by this method and discussed the formation mechanism through the simple particle heating/melting mechanism, which is basically different from the mechanism in the conventional pulsed laser ablation in liquid.
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  • Mitsuo KAWASAKI
    2012 Volume 40 Issue 2 Pages 88-
    Published: 2012
    Released: July 16, 2020
    JOURNALS FREE ACCESS
    Mass production at low cost is the biggest challenge that one faces in preparation of metallic nanoparticles by the laser ablation method in liquid. The use of ketone-suspended thin metal fl akes or fi ne metal oxide powders as the material allowed to interact with intense nanosecond laser pulses is one promising solution for maximizing the productivity of metal nanoparticles. This paper introduces how the system brings about the highest-ever productivity for laser synthesis of e.g., Cu nanoparticles at the rates ranging from 1.5 to 10 mg W‒1min‒1. This is still far from what is needed for industrial applications of metal nanoparticles such as conductive pattern making with a highly concentrated nanoparticle solution, and this paper also addresses how one may possibly fi ll this technical gap.
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  • Tsuyoshi ASAHI
    2012 Volume 40 Issue 2 Pages 94-
    Published: 2012
    Released: July 16, 2020
    JOURNALS FREE ACCESS
    A novel method for tailoring organic nanoparticle colloids is described. Laser ablation of organic microcrystalline powders in a poor solvent has opened new horizons for the synthesis of nanoparticles because the powder sample is converted directly into a stable colloidal solution without additives and chemicals. By tuning the laser wavelength, the pulse width, and the laser fl uence, we can control the size and phase of the nanoparticles. We demonstrate examples of nanoparticle colloid preparation for various organic compounds and describe their characteristics. We discuss the formation mechanism in terms of the laser-induced fragmentation of organic solids and consider the potential application of aqueous organic nanocolloids free from any additives and chemicals.
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  • Tetsuo SAKKA
    2012 Volume 40 Issue 2 Pages 100-
    Published: 2012
    Released: July 16, 2020
    JOURNALS FREE ACCESS
    The optical emission spectroscopy of the plume formed by liquid-phase laser ablation and its application to underwater in-situ elemental analysis (underwater laser-induced breakdown spectroscopy, underwater LIBS) are reviewed. Since the spectral deformation due to high density in the plume is a major problem, we overviewed the characterization of the plume, its formation mechanism, and the effects of a cavitation bubble. Based on the plume’s properties, we discuss a laser irradiation scheme, such as the double-pulse or long-pulse irradiation, to improve the emission spectra. Finally some applications of underwater emission spectroscopy as an in-situ elemental analysis are described.
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  • Hiroyuki NIINO, Yoshizo KAWAGUCHI, Tadatake SATO, Aiko NARAZAKI
    2012 Volume 40 Issue 2 Pages 106-
    Published: 2012
    Released: July 16, 2020
    JOURNALS FREE ACCESS
    We reviewed a one-step method to fabricate a microstructure on a silica glass plate using laser-induced backside wet etching (LIBWE), which is one media-assisted laser processing method based on liquid laser ablation with a conventional pulsed laser at UV or visible wavelength. Well-defined deep microtrenches without cracks and chipping formations on the glass plate were fabricated by LIBWE. The system allows us to use rapid prototyping of high precision surface microfabrication of the glass and other transparent materials as laser direct-write processing in conventional atmospheric environments.
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Laser Original
  • Takeshi TSUJI, Masato YASUTOMO, Takeshi MIZUKI, Masaharu TSUJI, Hideya ...
    2012 Volume 40 Issue 2 Pages 111-
    Published: 2012
    Released: July 16, 2020
    JOURNALS FREE ACCESS
    An effi cient method to prepare surface-assisted laser desorption ionization (SALDI) substrates which are used for mass spectrometry of biomolecules has been developed. Gold nanoparticles used as the matrix of SALDI substrate are prepared by laser ablation in liquids. To deposit the colloidal nanoparticles, electrophoresis, instead of dropping the colloidal solution onto a substrate reported in the previous study, is used, because the colloidal nanoparticles prepared by laser ablation in liquids are electronically charged. It is demonstrated that the thickness and the surface morphology of SALDI substrates are conveniently controlled by adjusting the concentration of colloids. The SALDI effi ciency for substrates prepared from colloids with higher concentrations was higher. The infl uence of the thickness and the surface morphology on the SALDI effi ciency was discussed.
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  • Shunsuke KAGAYA, Yoshitaka EHARA, Yoshitaka KITAMOTO, Hiroshi FUNAKUBO ...
    2012 Volume 40 Issue 2 Pages 117-
    Published: 2012
    Released: July 16, 2020
    JOURNALS FREE ACCESS
    A colloidal solution of InP nanoparticles was prepared by laser ablation in liquid. An InP target was irradiated in DI water, ethanol, and hexane with a Nd:YAG laser (1064 nm, 8 ns, 10 Hz). Indium metal nanoparticles were formed as a by-product during the preparation of InP nanoparticles by laser ablation in liquid. The primary particle size did not depend on the solvent or the energy density of laser. Nanoparticles were well-dispersed in ethanol by electrostatic repulsion, and they aggregated in DI water and hexane. The zeta potential of the nanoparticles in ethanol was ‒ 76 mV. Phosphoric acid was detected in the solvent when the DI water was used as a solvent for laser ablation in liquid. The InP target was decomposed into indium and phosphorus, and phosphorus reacted with the solvent.
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  • Shuichi HASHIMOTO
    2012 Volume 40 Issue 2 Pages 122-
    Published: 2012
    Released: July 16, 2020
    JOURNALS FREE ACCESS
    Pulsed laser-induced morphological transformation and size-reduction of colloidal gold nanoparticles in the aqueous phase were investigated using transient absorption spectroscopy and transmission electron microscopy (TEM). Femtosecond laser-induced fragmentation of gold nanoparticles within 100 ps after the laser pulse is interpreted in terms of the Coulomb explosion mechanism. On the other hand, nanosecond laser-induced size-reduction of gold nanoparticles is in good agreement with the photothermal evaporation mechanism that is based on heating of particles to temperatures above the boiling point of gold (3100 K). Here, the experimentally observed fragmentation thresholds were wellreproduced by simulations based on electron and lattice temperature models and by considering the dissipation of heat into the surrounding medium. The numerical method described herein has the advantage of identifying the fragmentation mechanism by considering pulse duration- and energydependent thresholds. To-date there is no other convenient measures to distinguish between the photothermal evaporation and the Coulomb explosion mechanisms.
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  • Vladimir SVRCEK, Davide MARIOTTI, Koiji MATSUBARA, Michio KONDO
    2012 Volume 40 Issue 2 Pages 128-
    Published: 2012
    Released: July 16, 2020
    JOURNALS FREE ACCESS
    We report on investigations of silicon nanocrystals (Si-ncs) surface engineering and subsequent integrations into sub-micrometer structures induced by nanosecond laser processing in water. We present that easy and low-cost methods through nanosecond laser processing in water allow of Si-ncs integration self-assemblies ranging several micrometers and sub-micron spherical particles. Room temperature photoluminescent properties were preserved in these particles.
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  • Yoshie ISHIKAWA, Naoto KOSHIZAKI, Alexander PYATENKO
    2012 Volume 40 Issue 2 Pages 133-
    Published: 2012
    Released: July 16, 2020
    JOURNALS FREE ACCESS
    We investigated a new fabrication technique for spherical particles by pulsed laser melting in liquid. In this technique, nanoparticles dispersed in liquid were melted by nanosecond pulsed laser irradiation with adequate fl uences, and the formed droplets became spherical particles after cooling. We investigated the infl uences of laser wavelength, fl uence, and dispersion medium on the obtained particles by irradiating the laser on titanium dioxide nanoparticles dispersed in ethanol and deionized water. We confirmed nanometer-sized sphere formation with submicrometer spheres by laser irradiation at relatively high laser fl uence.
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Regular Paper
Laser Original
  • Masahiro TOYODA
    2012 Volume 40 Issue 2 Pages 137-
    Published: 2012
    Released: July 16, 2020
    JOURNALS FREE ACCESS
    This paper reports the beam wave fl uctuations caused by strong atmospheric turbulence. These beam wave fl uctuations are estimated by numerical calculations carried out using moment equation analysis with thin phase screen approximation. The scintillation index for a plane wave is calculated as a function of a parameter concerning the intensity of atmospheric turbulence, and the result is in good agreement with previous studies. Transmission of the beam radius dependence of a scintillation index is calculated using the first and second moments of wave intensity. The largest scintillation index is obtained when the beam radius size equals (λ z/2π )1/2. The scintillation index of a beam wave is also evaluated using the Rytov approximation method, which is based on perturbation analysis.
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Laser Letter
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