| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method for cooling an optical fiber 7 under drawing which is capable of lessening Rayleigh scattering and is capable of drastically lessening the attenuation of the optical fiber. SOLUTION: The optical fiber is cooled by contact with at least one cooling fluid in at least one cooling zones 10, 11, 14, 19 and 18 and high-speed cooling 10 and 14, i.e., cooling faster than cooling in circumferential air are executed. Low-speed cooling 11 and 19, i.e., cooling slower than the cooling in the circumferential air are executed, by which the temperature of the fiber 7 in an intermediate zone 105 arranged between the two cooling zones is regulated to 1,200 to 1,700 deg.C in the case of silica glass giber.</p> |
