Manufacture of depressed index optical fibers
AssigneeLucent Technologies Inc.
InventorsYoram De Hazan, John Burnette MacChesney, Thomas Edward Stockert, Christopher Alan White
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Abstract
The process time required for fluorine doping of porous silica bodies to produce fluorine doped preforms for the manufacture of depressed index optical fibers is reduced by separating the doping step into a predeposit step, where “excess” fluorine is deposited on the silica particles, and a drive-in step where atomic fluorine is distributed into the silica particles. The drive-in step is conveniently combined with the sintering or consolidation step to further enhance the efficiency of the doping process.
Claims5
Process for the manufacture of optical fibers comprising:
- (a) preparing an optical fiber preform,
- (b) heating the preform to the softening temperature, and
- (c) drawing an optical fiber from the preform the invention characterized in that the optical fiber preform is produced by:
- (i) preparing a porous silica body of silica particles,
- (ii) heating the porous silica body in a fluorine atmosphere for a period of 10-240 minutes to predeposit fluorine on the silica particles, and
- (iii) heating the porous silica body at a temperature greater than 1300° C., in an atmosphere devoid of fluorine, to consolidate the porous silica body into a preform.
Process for the manufacture of optical fiber preforms comprising:
- (a) preparing a porous silica body of silica particles, said porous silica body having a weight greater than 5 kg,
- (b) heating the porous silica body to a temperature in the range 800-1000° C. in a fluorine atmosphere for a period of 10-240 minutes to predeposit fluorine on the silica particles, and
- (c) heating the porous silica body at a temperature greater than 1300° C., in an atmosphere devoid of fluorine, to consolidate the porous silica body.
Dependencies are inferred from the claim text.