• Title/Summary/Keyword: Chemical laser

Search Result 889, Processing Time 0.024 seconds

Multiple Order Diffractions by Laser-Induced Transient Grating in Nematic MBBA Film

  • 김성규;김학진
    • Bulletin of the Korean Chemical Society
    • /
    • v.20 no.6
    • /
    • pp.705-711
    • /
    • 1999

  • The laser-induced transient grating method is applied to study the dynamics of the nematic MBBA film. The nanosecond laser pulses of 355 nm are used to make the transient grating and the cw He-Ne laser of 633 nm is used to probe the dynamics. Strong multiple order diffractions are observed at high nematic temperatures. The reordering process induced by the phototransformed state, which is the locally melted state from the nematic sample, is attributed to the main origin of the multiple order diffractions from the nematic MBBA. The characteristics of the multiple order gratings are discussed with the grating profiles simulated from the multiple diffraction signals.

  • https://doi.org/10.5012/bkcs.1999.20.6.705 인용 PDF

The Study of Two-dimensional Chemical Distribution about Soil using Laser Spectroscopy (레이저 분광법을 활용한 토양 2차원 화학적 분포도 검출 연구)

  • Yang, Jun-Ho;Yoh, Jai-Ick
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.45 no.6
    • /
    • pp.523-530
    • /
    • 2017

  • Laser-Induced Breakdown Spectroscopy (LIBS) which a plasma is irradiated at a specific wavelength depending on the material when a high-energy laser is irradiated, and a Raman spectroscopy which measures rotation and vibration in molecules as light-scattering phenomenon occurs, are attracting attention as a space exploration technology because of the advantages of high accuracy and real-time analysis, and the ability to perform long-range detection. In this study, the tendency of the laser spectrum according to the change of the soil component was analyzed by laser spectroscopy and the two - dimensional chemical distribution was conducted based on the trend of laser spectrum. We have also established the environment of Mars (4-7 torr) and lunar atmosphere (<1 torr) in experimental setup, to prove that it is possible to measure by difference of soil chemical composition using LIBS and Raman spectroscopy even in artificial space environment.

  • https://doi.org/10.5139/JKSAS.2017.45.6.523 인용 PDF KSCI