Title: Method for producing glass preform for optical fiber
Application Number: 85100803 Application Date: 1985.04.01
Publication Number: 1001401 Publication Date: 1986.07.09
Approval Pub. Date: Granted Pub. Date: 1993.05.26
International Classifi-cation: C03B37/018
Applicant(s) Name: Sumitomo Electric Industries Ltd. Address:
Inventor(s) Name: Hiroshi Kawauchi
Attorney & Agent: LUO CAIXI
Abstract:
     The process comprises manufacturing glass preform like lignate-ash, which consiste of core and wrapping layer, concentration or bulk of additives used for manufacture of outermost layer of the core is thicker than its concentration or its bulk for manufacture of its internal layer, and heating glass preform at least for some time in environment containing fluorine or fluoride to produce transparent glass preform and to make fluorine to selectively add to the wrapping layer of the glass preform.
Time: 10