| 摘要 |
<p>A method and apparatus for increasing the overcladding rate in optical fiber preform production while maintaining the integrity of the cladding glass quality. Two plasma torches are used, instead of just one, that are driven by the same power generator. The process includes the steps of supporting the preform on a lathe; providing first and second plasma torches having nozzles angled toward the preform; powering first and second plasma torches with a common generator such that the plasma torches create plasma flames directed toward a surface of the preform; introducing a quartz sand at a junction between the first plasma torch or alternatively between both torches, and the surface of the preform to fuse the quartz sand on the surface of the preform; and moving the preform with respect to the plasma torches. The second plasma torch may be provided upstream of the first plasma torch so as to preheat the surface before the fusing of the quartz sand by the first plasma torch, or may be located downstream thereof to post-heat the quartz sand after the initial fusing by the first plasma torch.</p> |
