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    PRODUCTION OF ARTICLE COMPRISING REFRACTORY DIELECTRIC SUBSTANCE
    1.
    发明专利
    PRODUCTION OF ARTICLE COMPRISING REFRACTORY DIELECTRIC SUBSTANCE 失效

    公开(公告)号：JPH11255530A

    公开(公告)日：1999-09-21

    申请号：JP27384898

    申请日：1998-09-28

    Applicant: LUCENT TECHNOLOGIES INC

    Inventor： FLEMING JR JAMES WILLIAM ,  PAFCHEK ROBERT M

    IPC: G02B6/00 ,  B01J19/08 ,  C03B20/00 ,  C03B29/02 ,  C03B37/012 ,  C03B37/014 ,  C03C23/00 ,  C03C25/62

    Abstract: PROBLEM TO BE SOLVED: To reduce both a surface impurity and a bulk impurity approximately without removing the surface of a refractory dielectric substance. SOLUTION: A refractory dielectric substance is heated by a plasma fire ball 12 under conditions capable of not causing the removal of a considerable amount of the surface part of a refractory dielectric substance 20 and sufficiently reducing both a surface impurity and a bulk impurity. Isothermal oxygen or an oxygen-containing plasma is used. At least 30% of a chlorine impurity at least 10 μm in depth can be reduced while simultaneously removing a hydroxyl group impurity. Consequently the concentration of an impurity to be a cause of a defect in the drawing treatment of a fiber from a preform can be reduced without requiring the removal of a considerable amount of the preform from the surface.

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