Method for producing highly pure glass preform for optical fiber
AssigneeSumitomo Electric Industries, Ltd.
InventorsGotaro Tanaka, Hiroo Kanamori, Futoshi Mizutani
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Abstract
A method for producing a glass preform for an optical fiber by an outside vapor-phase deposition method, which comprises forming fine glass particles by jetting gaseous glass raw material and fuel gas from a first burner to deposit the particles on a seed rod to form a soot rod at such a temperature that a specific bulk density of the soot rod being formed is low and subsequently heating the soot rod by a second burner so as to increase the bulk density of the soot and then sintering the soot rod to obtain a transparent glass preform for an optical fiber, by which method, a highly pure glass preform is produced in a good deposition yield without cracking.
Claims1
A method for producing a glass preform for an optical fiber by an outside vapor-phase deposition method, which comprises the steps of:
- forming glass soot particles by jetting and combusting gaseous glass-forming raw material and fuel gas from a first burner, in the presence of oxygen,
- depositing the particles on a seed rod with control being provided so as to form a soot rod at such a temperature that a specific bulk density .rho./.rho.0, wherein .rho. is a bulk density of the soot rod and .rho.0 is a bulk density of perfectly sintered glass, of the soot rod being formed is from 0.02 to 0.1,
- subsequently heating the soot rod by a second burner with control being provided so as to increase the bulk density of the soot rod to from 0.15 to 0.5, and then
- sintering the soot rod to obtain a transparent glass preform for an optical fiber.
Dependencies are inferred from the claim text.