| 摘要 |
PURPOSE:To obtain a preform rod for an optical fiber while preventing the eccentricity of the core by reducing the diameter of both ends of a quartz tube to a slightly larger inside diameter than the outside diameter of a quartz rod at prescribed positions, putting the quartz rod into the quartz tube, fixing the rod with support rings, and reducing the diameter of the tube with an oxyhydrogen burner. CONSTITUTION:A quartz tube 1 is attached to the chucks 2, 2 of a glass lathe, and the diameter of a plurality of parts of the tube 1 is reduced to a slightly larger inside diameter than the outside diameter of a quartz rod to be put into the tube with an oxyhydrogen burner 5 to form parts 6 having a reduced diameter. After inserting support rings 3, 3 into the parts of the tube 1 held by the chucks 2, 2, the quartz rod 4 is inserted into the rings 3, 3. The burner 5 is moved back and forth along the outside of the tube 1 to carry out the surface treatment of the inside of the tube 1 and the outside of the rod 4. After finishing the surface treatment, the diameter of the tube 1 is reduced at a stroke from one end to the other end to complete the desired preform. |
