| 摘要 |
PURPOSE: To provide a production method of the subject preform material, good in the adhesion between glass fine particles and the surface of a starting member and free from developing rutile-type TiO2 even when the glass fine particles contain titanium. CONSTITUTION: In this production method of an optical fiber preform material by exterior process, the surface of a starting member 3 consisting of a vitrified preform material is heated to 800-1250 deg.C and glass fine particles are accumulated on the surface. The particles may contain titanium. Thereby, a large-sized optical fiber preform material can be produced; and even by using such a large- sized preform material, high-quality optical fibers can still be produced. Even if the preform material is intended to obtain titanium-doped optical fibers, the titanium element can be efficiently incorporated into an SiO2 glass composition, thus titanium-doped optical fibers resistant to injury and fatigue can be obtained. |
