| 摘要 |
PURPOSE:To inexpensively obtain a high-quality optical fiber preform by depositing a porous body consisting of a glass fine particle on a rod-shaped support according to a VAD method, hanging one end of the support onto linear body, introducing their bodies into a heating furnace and dehydrating and vitrifying the porous body. CONSTITUTION:A porous body 4 consisting of glass fine particles is deposited on a rod-shaped support 3 or at the tip thereof by VAD method. Then one end of the support 3 on which the porous body 4 is deposited is hung on a linear body 1 (e.g., platinum linear body) and introduced into a heating furnace 5 and the porous body 4 is dehydrated and vitrified to provide the optical fiber preform 2. Thereby inlet 9 of the heating furnace 5 having thin diameter for only passing through the linear body 1 can be used. Consequently, positive pressure can be attained by only feeding a small amount of atmospheric gas and high-quality glass preform 2 can be obtained by suppressing entry of outer air into the furnace 5 and also expensive dopant gas used is reduced to small amount. |
