Bibliographic Details
| Title: |
Method for producing glass preform for single mode optical fiber |
| Patent Number: |
4,675,040 |
| Publication Date: |
June 23, 1987 |
| Appl. No: |
06/722,384 |
| Application Filed: |
April 12, 1985 |
| Abstract: |
A method for producing a glass preform for a single mode optical fiber comprising a core and a cladding, which method comprises depositing fine glass particle of a glass raw material on a periphery of a cylindrical seed member having a smooth and clean outer surface by flame hydrolysis to form a soot of the fine glass material, pulling out the seed member from the soot, inserting a core glass rod in a hollow portion of the soot and dehydrating and sintering a complex of a core rod and a cladding to produce a glass preform from which a single mode optical fiber having low attenuation of light transmission, particularly due to absorption by hydroxyl groups can be drawn. |
| Inventors: |
Tanaka, Gotaro (Yokohama, JPX); Mizutani, Futoshi (Yokohama, JPX); Yoshioka, Naoki (Yokohama, JPX); Kanamori, Hiroo (Yokohama, JPX) |
| Assignees: |
Sumitomo Electric Industries, Ltd. (Osaka, JPX) |
| Claim: |
What is claimed is |
| Claim: |
1. A method for producing a glass preform for a single mode optical fiber with diminished attenuation of light transmission including a core and a cladding, said method comprising the following steps |
| Claim: |
depositing fine glass particles on the peripheral surface of a cylindrical seed member having a smooth and clean outer surface by flame hydrolysis, to form a self supporting soot of said fine glass particles; |
| Claim: |
pulling out said seed member from said soot, to form a bore within said soot; |
| Claim: |
inserting a core glass rod in said bore of said soot which soot forms a cladding; and |
| Claim: |
dehydrating and sintering a complex of said core glass rod and said soot cladding to fuse them together to produce a glass preform. |
| Claim: |
2. A method according to claim 1, wherein the complex of the core and the cladding is sintered in an atmosphere comprising an additive to add it to the cladding. |
| Claim: |
3. A method according to claim 2, wherein the additive is a fluorine-containing compound and fluorine is added to the cladding. |
| Claim: |
4. A method according to claim 1, wherein the seed member is a rod or a tube formed from a material selected from the group consisting of quartz glass, carbon and aluminum. |
| Claim: |
5. A method according to claim 1, wherein the core glass rod is formed of pure silica glass. |
| Claim: |
6. A method for producing a glass preform for a single mode optical fiber with diminished attenuation of light transmission including a core and a cladding, said method comprising the following steps |
| Claim: |
pulling out said seed member from said soot cladding, to form a bore within said soot; |
| Claim: |
inserting a core glass rod in said bore of said soot which soot forms a cladding and which inserting results in a core-cladding complex; |
| Claim: |
providing a glass jacket around said core-cladding complex; and |
| Claim: |
dehydrating and sintering a complex of said core glass rod, said soot cladding, and said glass jacket to fuse them together to produce a core-cladding-jacket glass preform. |
| Claim: |
7. A method according to claim 6, wherein the jacket is a quartz tube. |
| Current U.S. Class: |
65/312; 65/182; 65DIG16 |
| Current International Class: |
C03B 37014; C03B 37018 |
| Patent References Cited: |
4125388 November 1978 Powers
4235615 November 1980 Rau et al. |
| Other References: |
Suda et al; Electronics Letters, 10/9/1980, vol. 16, No. 21; pp. 802-803. |
| Primary Examiner: |
Schor, Kenneth M. |
| Attorney, Agent or Firm: |
Cushman, Darby & Cushman |
| Accession Number: |
edspgr.04675040 |
| Database: |
USPTO Patent Grants |
