| 摘要 |
An optical fiber producing method and apparatus are provided in which sufficient pulling tension is applied to an optical fiber to enhance the twisting efficiency without affecting winding tension of a winding bobbin, whereby the PMD of the optical fiber can be reduced. In a method of producing an optical fiber in which, in a path where an optical fiber 11 is reeled out from a supply bobbin 10, taken up by take-up means 20, and wound by a winding bobbin 24, twists are alternately imparted to the optical fiber 11 by a twist imparting portion 18, a zone where a high tension load is allowed to be applied to the optical fiber without affecting winding tension of the winding bobbin is disposed, a twist is imparted in the zone, and, when tension immediately before the twist imparting portion is indicated by T (g), a free path length is indicated by L, a twisting amount is indicated by R (turns/m), and a and b are constants, the tension and free path length by which the twisting amount R approximated by "R = a × T × L b " is made "2" or more are set |
