STP954: Light Stripping of UV Dielectric Coatings

    Asmus, JF
    Maxwell Laboratories, Inc., San Diego, CA

    Oldenettel, JR
    Maxwell Laboratories, Inc., San Diego, CA

    Pages: 5    Published: Jan 1986


    Abstract

    High-performance ultraviolet lasers require optics with a tighter tolerance on surface figure than comparable visible and infrared systems. Consequently, the costs of large-aperture figured substrates can be quite high. When ultraviolet coatings become damaged through exposure to photons and/or halogen radicals, recoating is often performed in order to salvage such substrates. If the coating is not strippable, this entails the expense of regrinding and repolishing. We have found that the remains of damaged coatings of SiO2, LaF3, MgF2, and HfO2 can be removed with pulsed xenon flashlamp radiation. A train of shots at 30 J/cm2 is sufficient to dislodge a coating without damaging fused silica and Zerodur substrates. A pulselength of 600 microseconds was employed. Frequently, photochemical damage involves only the coating and not the substrate. In these instances flashlamp stripping may be employed to salvage the substrate without reworking the surface.

    Keywords:

    coating removal, coating stripping, dielectric coating, laser mirror, mirror damage, xenon flashlamp


    Paper ID: STP23139S

    Committee/Subcommittee: E13.01

    DOI: 10.1520/STP23139S


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