| 摘要 |
PURPOSE:To produce an optical fiber preform capable of improving the rate of growth of a glass layer, by supplying a flon gas to a chamber from the backside of a high-frequency plasma torch, and supplying a glass-forming main raw material to the space in front of the torch. CONSTITUTION:An oxygen plasma flame is generated by supplying oxygen to a high-frequency plasma torch 1 as shown in the figure as the arrows. A flon gas 12 is supplied through the reaction gas introducing line 2, and SiCl4 is introduced through the reaction introducing line 2A using oxygen gas as the carrier gas. The introduced reactants are made to react with each other at the lower part of the plasma flame in the reaction chamber 4, and an F-doped SiO2 glass layer is deposited on the target rod 6 made of quartz glass. The target rod 6 is rotated with a glass lathe 5, and a glass layer 7 is formed to the circumference of the target rod 6 along the longitudinal direction. |
