| 摘要 |
PURPOSE:To keep the length of meniscus part of an optical fiber preform to be shorter than that of the conventional process even by increasing the drawing speed of optical fiber. CONSTITUTION:An optical fiber preform 4 in a furnace core tube 2 is heated and melted with a heater 3 placed at the outer circumference of the furnace core tube 2 in a furnace 1 and an optical fiber 7 is drawn from the meniscus part 4a composed of the molten part of the optical fiber preform 4. In the above process for the drawing of an optical fiber 7, the optical fiber preform 4 above the meniscus part 4a is cooled with cooling gas blasted to the outer circumference of the furnace core tube 2 from a position above the heater 3. |
