| 摘要 |
PURPOSE:To impart high mechanical strength to an optical fiber, by drawing an optical fiber raw material heated and melted in a heating zone, passing the obtained optical fiber through a tube prior to winding and cooling the fiber with a gas introduced into the tube through the middle part thereof. CONSTITUTION:A preform 1 introduced into a heat source 2 is heated and melted in the heat source 2, drawn and wound round a winding drum 6. Prior to the winding on the drum 6, the preform 1 is passed through a gas tube 20 and cooled with gases 18', 18'' flowing along longitudinal direction of the optical fiber 9 at the middle part of the tube 20. |
