Fabrication of high-silica glass article
AssigneeAmerican Telephone and Telegraph Company, AT&T Bell Laboratories
InventorEliezer M. Rabinovich
Life of this patent
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Abstract
Incorporation of fluorine into a porous silica body, such as an unsintered body produced by a sol-gel method, by VAD or OVPO, reduces or eliminates bubble or pore formation upon re-heating of the glass formed by sintering of the porous material. Effective fluorine concentrations are between 0.01 and 5% by weight. The invention can be used advantageously in producing preforms and optical fiber.
Claims6
A method for fabricating an article comprising silica-containing glass, the method comprising the steps of:
- dispersing silica-containing material in a polar liquid to form a sol;
- gelling said sol to form a gel body;
- treating said gel body with heat to form a silica-containing glass body;
- and
- completing the fabrication of said article, Characterized In That
- said silica-containing material includes at least a first portion containing chemically bound fluorine and a second portion which is essentially free of chemically bound fluorine, the duration of said gelling step ranging from about 5 minutes to about 24 hours.
A method for fabricating an article comprising silicacontaining glass, the method comprising the steps of:
- dispersing silica-containing material in a polar liquid to form a sol;
- gelling said sol to form a gel body;
- treating said gel body with heat to form a silica-containing glass body;
- and
- completing the fabrication of said article, Characterized In That
- said silica-containing material includes at least a first portion containing chemically bound fluorine and a second portion which is essentially free of chemically bound fluorine, the amount of fluoride ion in said sol resulting from said dispersing step ranging from about 0.2 grams of F per 100 grams of SiO.sub.2 to about 6 grams of F per 100 grams of SiO.sub.2.
Dependencies are inferred from the claim text.