摘要 |
A method of making low loss glass optical waveguides, wherein at least one coating of glass soot is deposited by the flame hydrolysis process on a starting member. The starting member is removed from the soot preform leaving an aperture therein. While the preform is heated to its consolidation temperature, an atmosphere including a drying agent is caused to flow into the aperture and through the porous preform, thereby removing water from the preform while the soot is consolidated to form a dense glass article. The atmosphere contains optimal amounts of oxygen and drying agent to minimize leaching of dopant oxide from the preform. Since some of the dopant oxide is leached from the preform near the aperture, the central portion of the preform is initially provided with an excess amount of dopant oxide. The resultant draw blank is drawn into an optical waveguide filament.
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