A method for fusion of a pipe made of quartz glass for use as a preform for optical fibers

摘要

Object of the present invention is to provide a welding method for welding a dummy tube to a quartz glass tube which results in an excellent welding strength and which does not cause shrinking of the inner diameter at the welded portion. This problem can be solved by a welding method for welding a dummy tube (2) to a quartz glass tube (1) for use as an optical fiber preform, comprising chamfering the inner edge portion of the dummy tube (2) and/or the quartz glass tube (1) for use as the optical fiber preform before welding the quartz glass tube (1) for use as the optical fiber preform with the dummy tube (2), and then heat melting them to melt welding them together.