US4787927A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fabrication of optical fibers
Assignee: BTG International Ltd
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Filing: 1986-08-13
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Granted: 1988-11-29
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Expires: 2006-08-13
Abstract
Abstract A method of making a preform for drawing optical fibers includes the steps of depositing a dopant material 3 in a dopant carrier chamber 1, heating the dopant material to cause it to vaporise at a predetermined rate, depositing from a mixture of a source material (GeCl 4 , SiO 4 , O 2 ) and said vaporised dopant a mixture of solid components 8 and fusing said solid components to form a doped glass.
Inventors
- 👤 Robert J. Mears
- 👤 Laurence Reekie
- 👤 Simon B. Poole
- 👤 David N. Payne
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:51
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/14; H01S3/16; H01S3/17; C; C03; C03B; C03B37/00; C03B37/01; C03B37/012; C03B37/014; C03B37/018; C03B37/01807; G; G02; G02B; G02B6/00; G02B6/02; H01S3/05; H01S3/06; H01S3/063; H01S3/067; H01S3/08; H01S3/081; H01S3/083; C03B2201/00; C03B2201/06; C03B2201/30; C03B2201/34; C03B2201/40; G02B6/24; G02B6/26; G02B6/28; G02B6/293; G02B6/29346; G02B6/29358; G02B6/29359; G02B6/29379; G02B6/29395
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
132 words
A method of fabricating a preform for the manufacture of optical fibres incorporating a doped glass in which a dopant material is deposited in a dopant chamber and is subsequently vaporized from said chamber and deposited on the inner surface of a tubular glass member, comprising the sequential steps of: heating the dopant chamber to fuse said dopant to the chamber wall, subsequently heating said chamber to cause said dopant to vaporize at a predetermined rate, passing a gaseous source material through said dopant chamber to mix said dopant material with said source material, depositing from the mixture of said source material and said dopant material a mixture of solid components on said inner surface, and fusing said solid components on said inner surface to form a doped glass for said preform.
Claim 2
Independent Claim
132 words
A method of fabricating a preform for the manufacture of optical fibres incorporating a doped glass in which a dopant material is deposited in a dopant chamber and is subsequently vaporized from said chamber and deposited on the inner surface of a tubular glass member, comprising the sequential steps of: heating the dopant chamber to fuse said dopant to the chamber wall, subsequently heating said chamber to cause said dopant to vaporize at a predetermined rate, passing a gaseous source material through said dopant chamber to mix said dopant material with said source material, depositing from the mixture of said source material and said dopant material a mixture of solid components on said inner surface, and fusing said solid components on said inner surface to form a doped glass for said preform.
Claim 3
Dependent Claim
31 words
A method of fabricating a preform according to claim 1 characterised in that said method further includes the step of heating the dopant carrier chamber whilst maintaining a dehydrating atmosphere therein.
Claim 4
Dependent Claim
22 words
A method of fabricating a preform according to claim 1 characterised in that said dopant contains a rare-earth or transition metal element.
Claim 5
Dependent Claim
18 words
A method of fabricating a preform according to claim 3 characterised in that the rare-earth element is neodymium.
Claim 6
Dependent Claim
18 words
A method of fabricating a preform according to claim 3 characterised in that the rare-earth element is erbium.
Claim 7
Dependent Claim
18 words
A method of fabricating a preform according to claim 3 characterised in that the rare-earth element is terbium.
Claim 8
Dependent Claim
21 words
A method of fabricating a preform according to claim 1 characterised in that the dopant includes a plurality of impurity ions.
Claim 9
Dependent Claim
19 words
A method of fabricating a preform according to claim 7 characterised in that the dopant includes terbium and erbium.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-11-29 | 1992-05-30 | 1992-11-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-11-29 | 1996-05-30 | 1996-11-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-11-29 | 2000-05-30 | 2000-11-29 | $7700.00 | Window Closed / Lapsed |