| 摘要 |
PURPOSE:To manufacture an optical fiber preform having stable quality, in high efficiency, by pulling up a transparent glass rod continuously along axial direction under rotation, and carrying out the growth of a porous glass on the surface of the rod and the thermal vitrification of the porous glass. CONSTITUTION:A transparent glass rod 13 is pulled up continuously from the glass smelting furnace 17 by the aid of the pulling rod 12 pulled up along axial direction under rotation. In the course of the rotating and pulling-up operation of the rod 13 for the core, (i) fine particles of glass forming a clad are blasted from the nozzle 14 and deposited on the surface of the rod 13 to effect the growth of the porous glass 16 (corresponding top the clad), and (ii) the porous glass 16 is converted to a clad consisting of transparent glass by heating in a high-temperature furnace 15 to obtain an optical fiber preform. The glass smelting furnace 17 is preferably rotated coaxially to the glass rod 13 to the opposite direction. |
