| 摘要 |
A glass optical fiber waveguide preform is prepared by chemical reaction of vapor ingredients within a bait tube. As the reactants flow through the bait tube, a hot zone traverses the tube to cause the deposition of soot in a section of the tube just downstream of the hot zone. An axially disposed heater, which is located just downstream from the hot zone in the vicinity of the soot deposit, is mechanically coupled to the burner which generates the hot zone. The heater enhances the thermophoresis effect, thereby increasing deposition rate and efficiency. Also, a gas may be flowed over the surface of the heater to confine the reactant vapors to an annular channel adjacent the bait tube wall and to prevent soot deposition on the heater. The heater may comprise an enlarged end portion to cause soot to flow toward the bait tube wall in the deposition region.
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