| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical fiber drawing furnace in which heat transfer to an optical fiber is sufficiently carried out to draw even when a gas having a low heat conductivity such as argon is used. SOLUTION: In the optical fiber drawing furnace 1 for drawing an optical fiber preform 5 in which a furnace core pipe 3 is formed from a carbon based material and an inert gas is fed to the inside of a furnace core 6 from the vicinity of the lower part of the furnace core pipe 3, an inert gas flow passage 14 once extending to the upper side of the furnace core 6 from an inert gas feed port 12 formed in the vicinity of the lower end part of the furnace core pipe 3 and returning to the lower part of the furnace core 6 is provided. COPYRIGHT: (C)2003,JPO |
