Method for manufacturing optical fiber parent material, and method for manufacturing optical fiber
AssigneeSumitomo Electric Industries, Ltd.
InventorsSatoshi Tanaka, Tetsuya Haruna
Life of this patent
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Abstract
A method for manufacturing an optical fiber preform including a core part and a cladding part is disclosed. The method includes: adding an alkali metal to an inner surface of a silica-based glass pipe; etching the inner surface of the silica-based glass pipe to which the alkali metal is added; making a glass rod by collapsing the silica-based glass pipe after the etching; and making an optical fiber preform using the glass rod. The silica-based glass pipe is heated in the adding such that a surface temperature of the silica-based glass pipe falls within a temperature range of 1500° C. or higher to lower than 2000° C.
Claims9
A method for manufacturing an optical fiber preform including a core part and a cladding part, comprising:
- adding an alkali metal to an inner surface of a silica-based glass pipe;
- etching the inner surface of the silica-based glass pipe to which the alkali metal is added;
- making a glass rod by collapsing the silica-based glass pipe after the etching;
- and
- making an optical fiber preform using the glass rod,
- wherein the silica-based glass pipe is heated in the adding such that a surface temperature of the silica-based glass pipe falls within a temperature range of 1500° C. or higher to lower than 2000° C. while a space in which the silica-based glass pipe is held is kept at a positive pressure above atmospheric pressure of greater than 0 Pa and 20 Pa or less,
- wherein the silica-based glass pipe is heated by reciprocatively traversing a heat source a plurality of times, the heat source being an oxyhydrogen burner,
- wherein in the adding, a heating time per traverse of the reciprocatively traversing with which a surface temperature of a predetermined area of the silica-based glass pipe falls within the temperature range of 1500° C. or higher to lower than 2000° C. is 0.5 minute or longer and shorter than 40 minutes,
- wherein the heating time is a time during which a certain point in the silica-based glass pipe is heated to 1500° C. or higher, and
- wherein a traverse speed of the oxyhydrogen burner is 10 mm/min or greater and 165 mm/min or less.
A method for manufacturing an optical fiber using an optical fiber preform including a core part and a cladding part, comprising:
- adding an alkali metal to an inner surface of a silica-based glass pipe;
- etching the inner surface of the silica-based glass pipe to which the alkali metal is added;
- making a glass rod by collapsing the silica-based glass pipe after the etching;
- making an optical fiber preform using the glass rod;
- and
- drawing the optical fiber preform to manufacture an optical fiber,
- wherein the silica-based glass pipe is heated by reciprocatively traversing a heat source a plurality of times, the heat source being an oxyhydrogen burner,
- wherein in the adding, a heating time per traverse of the reciprocatively traversing with which a surface temperature of a predetermined area of the silica-based glass pipe falls within the temperature range of 1500° C. or higher to lower than 2000° C. is 0.5 minute or longer and shorter than 40 minutes,
- wherein the heating time is a time during which a certain point in the silica-based glass pipe is heated to 1500° C. or higher,
- wherein a traverse speed of the oxyhydrogen burner is 10 mm/min or greater and 165 mm/min or less, and
- wherein in the adding, a space in which the silica-based glass pipe is held is kept at a positive pressure above atmospheric pressure of greater than 0 Pa and 20 Pa or less.
Dependencies are inferred from the claim text.