| 摘要 |
PURPOSE:To prevent Si decomposed in using a fluorine-containing gas containing Si from mixing into SiO2 glass fine particle bodies when SiO2 glass fine particle bodies are vitrified and simultaneously fluorine is doped to provide a clad. CONSTITUTION:A rod 1 having glass fine particle bodies 12 capable of providing a clad and formed on a rod 10 for core and being a raw material of optical fiber is prepared. The rod 1 is vitrified under a fluorine-containing gas atmosphere containing Si in a heating furnace 2. In this time, SiF4 is previously reacted with O2 to be made in a state of SiO2 and Si is prevented from going into SiO2 glass fine particle bodies. Furthermore, heat of furnace is used for heat required in the reaction to make the process efficient. |
