STP1028: Admixture of SiO2 to Suppress TiO2 Crystallization

    Sites, JR
    Colorado State University, Fort Collins, CO

    Postek, JS
    Colorado State University, Fort Collins, CO

    Robinson, RS
    Colorado State University, Fort Collins, CO

    Schemmel, TD
    Colorado State University, Fort Collins, CO

    She, CY
    Colorado State University, Fort Collins, CO

    Pages: 4    Published: Jan 1988


    Abstract

    Crystallization of glassy TiO2 films used in optical coatings can be a problem in high power applications and may be a major limitation to the laser damage threshold. An attempt to suppress such crystallization involved mixing small amounts of SiO2 into TiO2 during the ion-beam sputter deposition process. An admixture of 5% SiO2 increased the crystallization onset temperature, determined by Raman spectroscopy, by approximately 150°C. The refractive index was relatively unaffected by the addition of 5% SiO2, dropping from 2.42 to 2.38. Optical loss, which shows a sharp increase near 350°C for pure TiO2, did not increase measurably for the films with SiO2 admixture of 5% or greater.

    Keywords:

    optical coatings, TiO, 2, SiO, 2, Raman spectroscopy, refractive index


    Paper ID: STP18571S

    Committee/Subcommittee: E13.08

    DOI: 10.1520/STP18571S


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