US4518407A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical fibre preform manufacture
Assignee: STC PLC
•
Filing: 1980-02-25
•
Granted: 1985-05-21
•
Expires: 2000-02-25
Abstract
Abstract A rod of silica 14 is inserted into a substrate tube 10 whose bore is lined with a layer 11 of material having a refractive index less than that of silica. This layer 11 is itself covered with a layer 12 of silica. The assembly of the rod and tube is drawn into fibre, or its components are fused together to form a solid cross-section optical fibre preform.
Inventors
- 👤 Philip W. Black
- 👤 John Irven
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 13:14
CPC Classifications
C; C03; C03B; C03B37/00; C03B37/01; C03B37/02; C03B37/025; C03B37/027; C03B37/02754; C03B37/012; C03B37/01205; C03B37/01211; C03B37/01225; C03B37/01248; C03B37/014; C03B37/018; C03B37/01807; C03B2201/00; C03B2201/02; C03B2201/06; C03B2201/08; C03B2203/00; C03B2203/10; C03B2203/22; C03B2203/28; C03B2205/00; C03B2205/12; C03B2205/14; C03B2205/16; Y; Y10; Y10S; Y10S65/00; Y10S65/15; Y10S65/16
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
119 words
A method of fabricating an optical fibre preform by utilizing a silica substrate tube having a first index of refraction comprising the steps of: coating said tube with a first layer of silica including a dopant sufficient to provide a cladding layer exhibiting an index of refraction less than that of said silica tube, coating said first layer with an inhibiting layer of substantially undoped silica to provide a barrier to prevent migration of said cladding layer dopant across said inhibiting layer, inserting a substantially undoped silica rod coaxially into said coated tube to provide a core of said optical fibre preform, and fusing together said coated tube and said rod to form a solid cross-section optical fibre preform.
Claim 2
Independent Claim
119 words
A method of fabricating an optical fibre preform by utilizing a silica substrate tube having a first index of refraction comprising the steps of: coating said tube with a first layer of silica including a dopant sufficient to provide a cladding layer exhibiting an index of refraction less than that of said silica tube, coating said first layer with an inhibiting layer of substantially undoped silica to provide a barrier to prevent migration of said cladding layer dopant across said inhibiting layer, inserting a substantially undoped silica rod coaxially into said coated tube to provide a core of said optical fibre preform, and fusing together said coated tube and said rod to form a solid cross-section optical fibre preform.
Claim 3
Independent Claim
137 words
A method of fabricating an optical fibre perform by utilizing a silica substrate tube having a first index of refraction comprising the steps of: coating said tube with a first layer of silica including a dopant sufficient to provide a cladding layer exhibiting an index of refraction less than that of said silica tube, coating said first layer with an inhibiting layer of substantially undoped silica to provide a barrier to prevent migration of said cladding layer dopant across said inhibiting layer, inserting a substantially undoped silica rod coaxially into said coated tube to provide a core of said optical fibre preform, holding said coated tube and said rod on a common axis, heating and collapsing and tube onto said rod, and fusing together said tube and said rod to form a solid cross-section optical fibre preform.
Claim 4
Independent Claim
137 words
A method of fabricating an optical fibre perform by utilizing a silica substrate tube having a first index of refraction comprising the steps of: coating said tube with a first layer of silica including a dopant sufficient to provide a cladding layer exhibiting an index of refraction less than that of said silica tube, coating said first layer with an inhibiting layer of substantially undoped silica to provide a barrier to prevent migration of said cladding layer dopant across said inhibiting layer, inserting a substantially undoped silica rod coaxially into said coated tube to provide a core of said optical fibre preform, holding said coated tube and said rod on a common axis, heating and collapsing and tube onto said rod, and fusing together said tube and said rod to form a solid cross-section optical fibre preform.
Claim 5
Dependent Claim
38 words
A method of making an optical fibre preform as claimed in claim 1 or 2, wherein said first layer of silica contains a dopant selected from the group consisting of boric oxide, fluorine, and boric oxide and fluorine.
Claim 6
Dependent Claim
36 words
A method of making an optical fibre preform as claimed in claim 1 or 2, wherein said first layer and said inhibiting layer are deposited by a reaction from which hydrogen and its compounds are excluded.
Claim 7
Dependent Claim
30 words
A method as claimed in claim 1 or 2, wherein said first layer and said inhibiting layer are formed of material produced by the direct oxidation of halides with oxygen.
Claim 8
Dependent Claim
56 words
A method as claimed in claim 1 or 2, wherein the substrate tube is a composite structure comprising an outer part and an inner part lining the bore of said outer part, said inner part being made of a material deposited upon the outer part by a reaction from which hydrogen and its compounds are excluded.
Claim 9
Dependent Claim
34 words
A method of making an optical fibre preform as claimed in claim 1 or 2, wherein said substantially undoped silica rod is produced by a reaction from which hydrogen and its compounds are excluded.
Claim 10
Independent Claim
165 words
A method of fabricating an optical fibre by utilizing a silica substrate tube having a first index of refraction comprising the steps of: coating said tube with a first layer of silica including a dopant sufficient to provide a cladding layer exhibiting an index of refraction less than that of said silica tube, coating said first layer with an inhibiting layer of substantially undoped silica to provide a barrier to prevent migration of said cladding layer dopant across said inhibiting layer, inserting a substantially undoped silica rod coaxially into said coated tube to provide a core of said optical fibre preform, holding said coating tube and said rod on a common axis, heating and collapsing one end of said tube onto said rod, commencing with the collapsed end, introducing said tube and said rod coaxially into a furnace, causing progessive collapsing and fusing of said tube onto said rod, and drawing a solid cross-section optical fibre from an end of the fused tube and rod.
Claim 11
Independent Claim
165 words
A method of fabricating an optical fibre by utilizing a silica substrate tube having a first index of refraction comprising the steps of: coating said tube with a first layer of silica including a dopant sufficient to provide a cladding layer exhibiting an index of refraction less than that of said silica tube, coating said first layer with an inhibiting layer of substantially undoped silica to provide a barrier to prevent migration of said cladding layer dopant across said inhibiting layer, inserting a substantially undoped silica rod coaxially into said coated tube to provide a core of said optical fibre preform, holding said coating tube and said rod on a common axis, heating and collapsing one end of said tube onto said rod, commencing with the collapsed end, introducing said tube and said rod coaxially into a furnace, causing progessive collapsing and fusing of said tube onto said rod, and drawing a solid cross-section optical fibre from an end of the fused tube and rod.
Claim 12
Dependent Claim
35 words
A method of making an optical fibre as claimed in claim 8, wherein said first layer of silica contains a dopant selected from the group consisting of boric oxide, fluorine, and boric oxide and fluorine.
Claim 13
Dependent Claim
33 words
A method of making an optical fibre as claimed in claim 8, wherein said first layer and said inhibiting layer are deposited by a reaction from which hydrogen and its compounds are excluded.
Claim 14
Dependent Claim
28 words
A method as claimed in claim 8, wherein said first layer and said inhibiting layer are formed of material produced by the direct oxidation of halides with oxygen.
Claim 15
Dependent Claim
56 words
A method as claimed in claim 10 or 11, wherein the substrate tube is a composite structure comprising an outer part and an inner part lining the bore of said outer part, said inner part being made of a material deposited upon the outer part by a reaction from which hydrogen and its compounds are excluded.
Claim 16
Dependent Claim
31 words
A method of making an optical fibre as claimed in claim 8, wherein said substantially undoped silica rod is produced by a reaction from which hydrogen and its compounds are excluded.
References Cited (Backward Citations)
GB1475496A
Cited
US4123483A
Cited
US4161505A
Cited
US3877912A
Cited
US4217027A
Cited
US4217027B1
Cited
JPS5181143A
Cited
US3980459A
Cited
US4087266A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-05-20 | 1988-11-19 | 1989-05-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-05-20 | 1992-11-19 | 1993-05-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-05-20 | 1996-11-19 | 1997-05-21 | $7700.00 | Window Closed / Lapsed |