| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide method for cooling an optical fiber under drawing while assuring mechanical strength by lessening attenuation. SOLUTION: High-speed cooling 10, i.e., cooling faster than cooling in the circumferential air, is effected in order to attain the end temperature of the high-speed cooling of the fiber 7 from the initial temperature of the fiber 7 and thereafter the low-speed cooling, i.e., cooling slower than the cooling in the circumferential air is effected in order to lower to the end temperature 11 of the low-speed cooling of the fiber 7 from the starting temp. of the low- speed cooling of the fiber 7.</p> |
