| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a primary preform for optical fibers, wherein the attenuation in optical fibers obtained is minimized. <P>SOLUTION: The method is for manufacturing a primary preform for optical fibers, using an internal vapour deposition process, wherein a gas flow 10 of doped undoped glass-forming gases is supplied to the interior of a hollow substrate tube 2 having a supply side 3 and a discharge side via the supply side thereof 3, wherein deposition of glass layers on the interior of the substrate tube 2 is effected as a result of the presence of a reaction zone, and wherein the gas flow 10 is subjected to a pre-treatment prior to being supplied to entry in the interior of the hollow glass substrate tube 2. <P>COPYRIGHT: (C)2012,JPO&INPIT |
