초록 ▼

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 tempe

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.

대표청구항 ▼

The method of forming a glass article comprising the steps of depositing on a starting member a coating of flame hydrolysis-produced glass soot to form a porous soot preform, the refractive index at the inner portion of said preform being greater than that at the outer portion thereof, removing said

The method of forming a glass article comprising the steps of depositing on a starting member a coating of flame hydrolysis-produced glass soot to form a porous soot preform, the refractive index at the inner portion of said preform being greater than that at the outer portion thereof, removing said starting member to form an aperture in said preform, disposing said preform in a furnace, flowing into said aperture a stream of an atmosphere comprising chlorine and oxygen, the concentration of chlorine being between 0.1 vol.% and 9.0 vol.% and the ratio (vol.% chlorine)2/(vol.% oxygen) being less than 1.0 vol.%, and heating said soot preform to a temperature within the consolidation temperature range for a time sufficient to cause said soot particles to fuse and form a dense glass layer.