The Review of Laser Engineering
Online ISSN : 1349-6603
Print ISSN : 0387-0200
ISSN-L : 0387-0200
Volume 14, Issue 11
Displaying 1-8 of 8 articles from this issue
  • Koichi TOYODA
    1986 Volume 14 Issue 11 Pages 934
    Published: November 28, 1986
    Released on J-STAGE: February 26, 2010
    JOURNAL FREE ACCESS
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  • Yoshiaki AKIMOTO
    1986 Volume 14 Issue 11 Pages 935-945
    Published: November 28, 1986
    Released on J-STAGE: February 26, 2010
    JOURNAL FREE ACCESS
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  • Akira SASAKI, Akifumi OGIWARA
    1986 Volume 14 Issue 11 Pages 946-952
    Published: November 28, 1986
    Released on J-STAGE: February 26, 2010
    JOURNAL FREE ACCESS
    Laser-beam deviation with thermal distortion of an internal-mirror He-Ne (λ= 633 nm) laser is measured using a two-dimensional position sensitive device. Typical values of beam deviation for a He-Ne laser are around±50 μrad for operation from a cold start, and depend on the twist angle of a laser tube. The values of beam deviation for an output and frequency stabilized He-Ne laser are ±3 μrad/h in the vertical direction and ±5 μrad/h in the transverse direction. The tube length of the stabilized laser is controlled to be constant, and also the laser-beam deviation is stabilized.
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  • Naohiro TANNO, Kenichi YOKOTO
    1986 Volume 14 Issue 11 Pages 953-959
    Published: November 28, 1986
    Released on J-STAGE: February 26, 2010
    JOURNAL FREE ACCESS
    The paper presents novel methods for one-way imaging by double-pulse transmission through a turbulent medium, using corrected wavefront generation due to degenerate four-wave mixing. The present methods are based on a principle that the mixing of a distorted object pulse with a pump pulse equivalently distorted through an identical turbulent medium produces corrected wavefront in a nonlinear medium in real-time. These methods require neither retroreflecting transmission of a phase-conjugate wave nor two fibers with the same length and quality. Two methods associated with the basic principle are presented and theoretically discussed with ability of arbitrary phase correction.
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  • Chobei YAMABE, Hiroyuki ISHIHARA, Hidenori AKIYAMA, Kenji HORII
    1986 Volume 14 Issue 11 Pages 960-964
    Published: November 28, 1986
    Released on J-STAGE: February 26, 2010
    JOURNAL FREE ACCESS
    When the high frequency corona discharge (HFCD) is superposed on the conventional double discharge, it has been confirmed that the laser output shows about 64% increase in the mixture of CO2 /N2/He=1/1/10 due to the suppression of glow-to-arc transition at atmospheric pressure.
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  • Oscillation Characteristi and the Quantification
    Takehiro WATANABE, Yoshitaro YOSHIDA, Chikara SHIMO
    1986 Volume 14 Issue 11 Pages 965-974
    Published: November 28, 1986
    Released on J-STAGE: February 26, 2010
    JOURNAL FREE ACCESS
    It is generally difficult to estimate shapes machined with laser beam analytically, because many complicated phenomena break out in machining, such as phase change, generation of plume, characteristics change of material. So, in this series, it is tried by numerical calculation to predict shapes machined with laser beam. In this case, important matters are quantification of output characteristics of oscillator, detailed observation of machining phenomena and construction of machining mechanism. In this paper, the characteristics of used laser beam are investigated which show the sharpness of tool in material processing with laser. Namely, the oscillated wave form, the beam profile and the beam divergence angle are measured of normal pulsed YAG laser. The oscillated wave form is shown as a train of rectangles in a short time. The half angle of beam divergence is 2-3 mrad in the oscillator and it shows about ten times of the value calculated with diffraction theory. The beam profile is approximately shown by Gaussian distribution whose skirt is cut with the beam diameter.
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  • Takayasu MOCHIZUKI, Ryosuke KODAMA, Chiyoe YAMANAKA
    1986 Volume 14 Issue 11 Pages 975-978
    Published: November 28, 1986
    Released on J-STAGE: February 26, 2010
    JOURNAL FREE ACCESS
    X-ray spectra from 0.53 μm wavelength laser-produced plasmas are investigated for the photon energy range of 0.1-3Ke V as a function of the atomic number Z. Several spectral humps are found to move towards higher energy side as Z increases. These series of the humps are interpreted as the transitions in K, L, M, N, O shells of ions. The square root of the photon energy at the spectral hump is found to be approximately linearly dependent on Z, suggesting that a semi-Moseley's law holds in the plasma x-rays. From this result liquid or solid cryogenic targets using Xenon or Krypton are found to be very useful as a practical x-ray source. A preliminary experimental result of the cryogenic target is presented and a practical system is proposed.
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  • 1986 Volume 14 Issue 11 Pages 979-997
    Published: November 28, 1986
    Released on J-STAGE: February 26, 2010
    JOURNAL FREE ACCESS
    Download PDF (2712K)
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