APPARATUS FOR PRODUCING OPTICAL FIBER PREFORM

摘要

PURPOSE:To easily and stably obtain a large-sized optical fiber preform free from dimensional change in longitudinal direction by producing a porous glass preform for clad using a specific apparatus and heating the preform to obtain transparent glass. CONSTITUTION:A glass rod 1 for a core for the deposition of silica soot is vertically placed in a reaction vessel 3 in a rotatable and vertically reciprocative manner and an oxyhydrogen flame burner 6 is fixed to the vessel. The core glass rod 1 is attached to a vertically movable integrated frame 4 and both ends of the rod are fixed with chucks 5. A porous glass preform 2 for clad is grown on the core glass rod 1 by the spray of glass soot and the deposition of the preform 2 is controlled preferably with a load cell 8 fixed to the frame 4. The obtained porous glass preform for clad is converted to a transparent glass by thermal dehydration to obtain an optical fiber preform.