| 摘要 |
<p>The present invention relates to a method for producing a preform, which is substantially free of OH impurities, for an optical fibre, wherein one or more quartz layers, which may or may not be doped, are deposited on the internal surface of a quartz glass support tube, in which method a furnace is moved axially with respect to the support tube, and after the quartz layers have been deposited the suport tube is contracted into a bar-shaped preform while being heated, wherein the furnace comprisees an electrical resistance furnace, in which furnace the support tube is rotated, with the space between the rotating support tube and the furnace being washed with an inert gas.</p> |
