STP1117: Optical Damage on SiO2 Cavity Mirrors Produced by High-Power VUV Laser Irradiation

    Takigawa, Y
    Osaka Electro-Communication University, Neyagawa, Osaka,

    Kurosawa, K
    Osaka Electro-Communication University, Neyagawa, Osaka,

    Okuda, M
    Osaka Electro-Communication University, Neyagawa, Osaka,

    Sasaki, W
    Osaka Electro-Communication University, Neyagawa, Osaka,

    Yoshida, K
    Osaka Electro-Communication University, Neyagawa, Osaka,

    Fujiwara, E
    Osaka Electro-Communication University, Neyagawa, Osaka,

    Kato, Y
    Osaka Electro-Communication University, Neyagawa, Osaka,

    Inoue, Y
    Osaka Electro-Communication University, Neyagawa, Osaka,

    Pages: 11    Published: Jan 1990


    Abstract

    We report observation results about damages on SiO2 mirror surfaces. The damages were made when the mirrors were used as a cavity reflector for the Ar and Kr excimer lasers. The surface profile, transmission and reflectance spectra, and X-ray photoelectron spectra show that bulk Si is isolated in the surface layer which was exposed to 9.8eV photons from the Ar excimer laser. The Kr excimer laser, whose photon energy is 8.5eV, does not induce such a phenomenon. The Ar excimer laser photons, surmounting the fundamental band gap of SiO2, 9eV, are considered to create high density excitons that induce the Si-O bond breaking and Si isolation.

    Keywords:

    VUV laser, rare gas excimer laser, quartz glass mirror, mirror damage, x-ray photoelectron spectroscopy


    Paper ID: STP26496S

    Committee/Subcommittee: E13.15

    DOI: 10.1520/STP26496S


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