| 摘要 |
PURPOSE:To prepare an oxide powder rod for providing an optical fiber having large aperture number, by improving a heat-treating means for a glass raw material in gaseous phase in the preparation of the oxide powder rod comprising a core layer and a clad layer. CONSTITUTION:The rotating rod 4 is turned at a temporary line position, oxide powder for core is jetted from the jetting device 1, and oxide powder for clad from the jetting device 3 respectively. In the operation, a glass raw material SiCl4 in gaseous phase containing a dope agent GeCl4 is hydrolyzed by oxyhydrogen flame in the side of the jetting device 1 into oxide powder, blown to the tip of the rotating rod 4, and deposited to form the core layer 5. While, in the side of jetting devive 3, a glass raw material SiCl4 in gaseous phase containing a dope agent FS6 is heat-treated with O2 in the non-flame type heater 2 of the frequency heating type, etc. into oxide powder, and deposited on the outer periphery of the layer 5 to form the clad layer 6. The rod 4 is raised depending upon the deposition speed, consequently the oxide powder rod 7 with a given length is formed. |
