PRODUCTION OF OPTICAL FIBER PREFORM

摘要

PURPOSE:To provide a method capable of sufficiently supporting a porous glass preform for optical fibers even if the preform is large-sized and free from lowering of transmission loss characteristics in vitrifying a porous glass preform for optical fibers. CONSTITUTION:A porous glass preform for optical fibers obtained by depositing porous glass for a clad around a core is hung using a jig and introduced into a furnace to vitrify the preform. In this time, a jig made of platinum is used as the jig. Whole the jig may be made of platinum or only pin 5 may be made of platinum when the preform 1 is connected to the top of the jig 3 by the pin 5. Since platinum has high mechanical strength, the jig can withstand large- sized preform and is not eroded by a fluorine-based gas even if the interior of a furnace is kept in a fluorine-based gas atmosphere.