| 摘要 |
PURPOSE:To reduce the cracking of an optical fiber preform due to heat treatment by finishing the heating by a heating source moved in the longitudinal direction of the optical fiber preform provided with a glass supporting body at the end of the glass supporting body. CONSTITUTION:The burner 6 is moved to the glass supporting body 4 as shown by a burner 6', and heating is completed. When the burner 6 is moved many times with respect to the preform 3 due to drawing, a flame, etc., the burner 6 is preferably moved past the A-B line into the rod-shaped or tubular supporting body 4 each time. When the supporting body 4 is connected to both ends of the optical fiber preform 3, the process is followed in the same way. Namely, the burner 6 is moved to the right in the figure with respect to the preform 3 into the supporting body 4. The burner 6 is then moved to the left into the left supporting body 4 or 5, and the heat treatment by the burner 6 is completed. |
