Abstract: It is possible to wind an optical fiber up to the vicinity of an edge of a flange of a bobbin, and prevent a winding collapse of the optical fiber without increasing work steps. In a state in which the optical fiber coated with a coating resin is wound around the bobbin, a resin film that does not include a plasticizer is covered so as to be in direct contact with an outer circumference of the optical fiber, and the optical fiber is stored.

Abstract: An optical fiber producing method and apparatus for producing an optical fiber in which, in a path where an optical fiber is reeled out from a supply bobbin, taken up by take-up means, and wound by a winding bobbin, twists are alternately imparted to the optical fiber by a twist imparting portion. 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×Lb” is made “2” or more are set.

Abstract: 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.