JUNCTURE OF OPTICAL FIBER-CONTAINING METALLIC TUBE

摘要

PURPOSE:To prevent melt-down of a weld metal and overheating of optical fibers at the time of welding by seal-welding covering tubes and a connecting tube and inserting backing materials into the covering tubes and the connecting tube. CONSTITUTION:The optical fibers 1 are exposed from the covering tubes 5 by the length required for connection and the connecting tube 11 is fitted onto the covering tubes 5 and is retreated so as not to cover the exposed point. The backing tubes 21 are inserted into the covering tubes 5 while allowing the optical fibers 1 to pass therein and are retreated not to cover the exposed part in the same manner as for the connecting tube 11. The joint part 3 of the optical fibers 2 is then heated to connect the optical fibers 1. The lining tubes 21 are positioned and adjusted to the seal-welded part S. The connecting tube 11 is pulled back to cover the spacing between the lining tubes 21 and the spacings between the peripheral faces of the covering tubes 5 and the ends of the connecting tube 5 are seal-welded S. Since the backing materials are provided in such a manner, the melt-down and the overheating of the optical fibers at the time of welding are prevented.