| 摘要 |
PROBLEM TO BE SOLVED: To provide a wire drawing furnace manufacturing an optical fiber having a small Rayleigh scattering loss by simple temperature control performed with a small energy consumption for a wire drawing furnace having an arbitrary length without necessitating a concomitant slow cooling furnace. SOLUTION: The wire drawing furnace 20 has a wire drawing furnace body 10 in which an optical fiber preform 1 is arranged, and a heater 13 which is arranged in the wire drawing furnace body 10 and heats the optical fiber preform 1. In the wire drawing furnace 20, the optical fiber is manufactured by cooling an optical fiber body 2, obtained by heating and drawing the optical fiber preform 1, to room temperature. The wire drawing furnace body 10 has a slow cooling zone 11, where the temperature is continuously lowered from 1,600°C in accordance with the distance in the longitudinal direction, at a lower part of the heater 13, and can variably regulate the setting temperature Tmin at the lowermost part 10a of the slow cooling zone 11 within a range not higher than 1,600°C. COPYRIGHT: (C)2007,JPO&INPIT |
