STP911: Laser-Induced Emission and Laser Damage of Optical Components

    Nichols, DB
    Boeing Aerospace Company, Seattle, WA

    Morris, DJ
    Boeing Aerospace Company, Seattle, WA

    Bailey, MP
    Boeing Aerospace Company, Seattle, WA

    Hall, RB
    Boeing Aerospace Company, Seattle, WA

    Pages: 6    Published: Jan 1985


    Abstract

    The role of point defects in the failure of high-power laser optical components has been the subject of many analytical and experimental studies. We describe a related surface effect, newly observed, which is visible-wavelength emission from component surfaces undergoing exposure to infrared laser radiation at levels far below the visible damage threshold. This effect has been observed on a variety of optical components, including coated reflectors and uncoated window materials. In large-spot tests, the total emission amplitude exhibits strong time dependence. Spatial imaging shows distinct point sources of the visible emission, some of which recur during multiple-shot tests. Spatial correlations between (a) microscopic surface defects visible before damage, (b) emission points due to laser irradiation, and (c) damage points due to high-power laser irradiation, have been studied using spatial mapping techniques with indexing uncertainties of ∼25 μm. For dielectric coatings, a strong correlation is observed between the recurrent visible emission points, and pulsed laser damage points.

    Keywords:

    damage precursors, high-power laser optics, infrared lasers, laser damage, microscopic surface mapping, multilayer dielectric films, optical components, point defects, pulsed DF chemical lasers, surface diagnostics, visible-wavelength emission


    Paper ID: STP28997S

    Committee/Subcommittee: E13.01

    DOI: 10.1520/STP28997S


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