| 摘要 |
PURPOSE:To provide a process capable of producing a porous preform for an optical fiber in high yield with a simple apparatus without damaging a glass rod for core. CONSTITUTION:The objective process is composed of a step to obtain a long thin porous formed material having circular cross section and one or plural through holes extending in the longitudinal direction by extrusion-molding a plastic material composed mainly of silica and a step to insert a glass rod into the above through hole. |
