STP689: CW Laser Damage in AR Coated Alkaline Earth Fluorides at 3.8 µm

    Detrio, JA
    University of Dayton Research Institute, Dayton, Ohio

    Petty, RD
    University of Dayton Research Institute, Dayton, Ohio

    Pages: 8    Published: Jan 1979


    Abstract

    We have measured the damage threshold of AR coated SrF2 and oriented single crystals of CaF2 using a CW chemical laser operating at approximately 3.8 m. The samples were irradiated for three seconds up to a total power of 8.4 kW. The specimens all failed at a power density of 22 kW/cm2 over a 0.3 cm2 area. The failure mode was not catastrophic and is believed to consist of plastic deformation due to compressive loading in the center of the irradiated region on the exit surface. The surface absorption is the dominant contributor to the failures. A novel statistical approach to defining the damage threshold and assessing the confidence level of the data was used.

    Keywords:

    Antireflection coatings, calcium fluoride, cw laser damage, DF laser, fusion cast, laser damage, laser window, single crystal, strontium fluoride


    Paper ID: STP39108S

    Committee/Subcommittee: F01.02

    DOI: 10.1520/STP39108S


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