| 摘要 |
PURPOSE:To prevent an optical fiber from the reduction of strength and to detect disconnection precisely by inserting metal which is a conductive element for detecting disconnecting into a glass tube similar to the optical fiber, inserting the tubes into through holes formed into a preform and then drawing the preform. CONSTITUTION:Two through holes are symmetrically formed into a clad part 2 of the preform 6. After inserting a platinum wire into a quartz tube, its one end is sealed, its inside is reduced at its pressure from the other end under said state and the whole quartz tube is heated successively from the sealed part to unify the platinum wire with the quartz tube. The formed quartz wires are inserted into the through holes 7 of the preform 6 and the whole preform 6 is heated to unify the quartz tube with the preform 6 and to form the preform 6 including the conductive element. Consequently, an optical fiber characterized by sufficient mechanical strength and precise detection of disconnection can be easily produced. |
