| 摘要 |
<p>A glass optical waveguide preform is formed by chemical reaction of gaseous and/or vapourised ingredients (A and B) within a glass substrate tube (52). A reactant feed tube (50) extends Into a first end of the substrate tube (52). One of the reactants (A) flows through the feed tube (50), and another (B) flows through the annular channel between the feed (50) and substrate (52) tubes. The reactants (A and B) combine just downstream of the end of the feed tube (54) and react to form particulate material, of which at least a portion is deposited on the substrate tube (52). The output end of the feed tube (50) traverses (58, 60) the substrate tube (52) so that the region of maximum soot deposition moves along the length of the substrate tube. A hot zone (54, 56) traverses (18a', 18b') the substrate tube (52) in synchrony (58) with the feed tube (50) to sinter the deposited soot.</p> |
