| 摘要 |
A glass optical waveguide filament preform is prepared by chemical reaction of vapor ingredients within a glass substrate tube. As the reactants flow through the substrate tube 52, a hot zone 54 traverses the tube to cause the deposition of sooty reaction products 44' in the region of the hot zone, the soot being consolidated to glass layer 48'. A baffle tube 50 extends into that end of the substrate tube into which the reactants flow. The baffle tube 50, which traverses the substrate tube along with the burner 56, ends just short of the hot zone 54 so that no soot is deposited thereon. A gas flowing from the baffle tube creates a gaseous body or mandrel 66 which confines the flow of reactant vapors to an annular channel adjacent the substrate tube wall 52 in the hot zone, thereby increasing deposition rate and efficiency. <IMAGE> |
