Patent US5754175A successfully refreshed from Google Patents.
Patent US5175779A successfully refreshed from Google Patents.
US5175779A
Expired / Lapsed
US
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Method of forming an optical fibre coupler and a coupler so formed
Assignee: British Telecommunications PLC
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Filing: 1990-03-20
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Granted: 1992-12-29
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Expires: 2010-03-20
Abstract
Abstract Six secondary optical fibres (20) are located about and parallel to a central optical fibre (21) by a capillary tube (22) to form a fibre bundle which is then formed into a fused, tapered coupler in which the tapering is stopped when the proportions of light coupled out of the central fibre (21) at 1.3 and 1.53 μm are first equal. The fusion process can provide sufficient fusion between the central fibre and each secondary fibre to provide a 1 to (n+1) coupler where n is the number of secondary fibres. This method provides a coupler which is wavelength-flattened between 1.3 and 1.53 μm using similar fibres.
Inventors
- 👤 David B. Mortimore
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 18:46
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/24; G02B6/26; G02B6/28; G02B6/2804; G02B6/2856
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
82 words
A method of forming an optical fibre coupler including the steps of a) locating two or more secondary optical fibres about a central optical fibre to form a fibre bundle such that all the secondary fibres are similarly disposed with respect to every one of the other fibres; and b) forming a fused, tapered coupler from the fibre bundle the tapering being stopped when the proportions of light coupled out of the central fibre at two distinct predetermined frequencies are first equal.
Claim 2
Independent Claim
82 words
A method of forming an optical fibre coupler including the steps of a) locating two or more secondary optical fibres about a central optical fibre to form a fibre bundle such that all the secondary fibres are similarly disposed with respect to every one of the other fibres; and b) forming a fused, tapered coupler from the fibre bundle the tapering being stopped when the proportions of light coupled out of the central fibre at two distinct predetermined frequencies are first equal.
Claim 3
Dependent Claim
24 words
A method as in claim 1 in which the fibres are located relative to each other by respective holes in a cylindrical support member.
Claim 4
Dependent Claim
20 words
A method as in claim 2 in which each hole is lubricated with methanol before insertion of the respective fibre.
Claim 5
Dependent Claim
20 words
A method as in claim 1 in which the fibre bundle is twisted prior to forming the fused, tapered coupler.
Claim 6
Dependent Claim
22 words
A method as in claim 1 or 4 in which the fibres are located relative to each other by a capillary tube.
Claim 7
Dependent Claim
41 words
A method as in claim 1, 2, 3 or 4 in which degree of fusion is controlled by controlling the temperature of the fusion to obtain a predetermined tension profile exerted on the fibres during formation of the fused tapered coupler.
Claim 8
Dependent Claim
49 words
A method of forming a coupler as in claim 1, 2, 3 or 4 in which there are n secondary fibres, the formation of the coupler providing sufficient fusion between the central fibre and each secondary fibre to provide a 1 to (n+1) coupler at the two predetermined frequencies.
Claim 9
Dependent Claim
49 words
A method of forming a coupler as in claim 1, 2, 3 or 4 in which there are n secondary fibres, the formation of the coupler providing sufficient fusion between the central fibre and each secondary fibre to provide a 1 to n coupler at the two predetermined frequencies.
Claim 10
Dependent Claim
86 words
A method as in claim 8 in which there are seven standard system matched cladding fibres held in an hexagonal close packed array by a borosilicate capillary prior to fusion of the fibres, the coupler is elongated during fusion at approximately 200 μm/sec and tension applied to the fibres during formation of the coupler starts at 2 gm reducing linearly to 0.9 gm which latter tension is maintained until the proportions of light coupled out of the central fibre at two predetermined frequencies are first equal.
Claim 11
Dependent Claim
26 words
A method as claimed in claim 1, 2, 3 or 4 in which the secondary fibres are equidistantly spaced in a ring about the central fibre.
Claim 12
Dependent Claim
25 words
A method as in claim 1, 2, 3 or 4 in which there are an even number of secondary fibres, which are grouped in pairs.
Claim 13
Dependent Claim
21 words
A method as in claim 1, 2, 3 or 4 in which the light transmitted by the central fibre is monitored.
Claim 14
Dependent Claim
23 words
A method as in claim 1, 2, 3 or 4 in which the light coupled into at least one secondary fibre is monitored.
Claim 15
Dependent Claim
19 words
A method as in claim 3 in which the total light coupled into all the secondary fibres is monitored.
Claim 16
Dependent Claim
74 words
An optical coupler comprising a fused tapered coupler having a coupling region in which light propagating in a central optical fibre is coupled into two or more secondary fibres, all the secondary fibres being similarly disposed with respect to every one of the other fibres and the coupling region having a length which is the minimum distance for which the coupling ratio at two preselected wavelengths is first equal during formation of the coupler.
Claim 17
Dependent Claim
74 words
An optical coupler comprising a fused tapered coupler having a coupling region in which light propagating in a central optical fibre is coupled into two or more secondary fibres, all the secondary fibres being similarly disposed with respect to every one of the other fibres and the coupling region having a length which is the minimum distance for which the coupling ratio at two preselected wavelengths is first equal during formation of the coupler.
Claim 18
Dependent Claim
23 words
An optical coupler as in claim 15 in which there are n secondary fibres and the coupler is a 1 to (n+1) coupler.
Claim 19
Dependent Claim
23 words
An optical coupler as in claim 15 in which there are n secondary fibres and the coupler is a 1 to n coupler.
Claim 20
Dependent Claim
22 words
An optical coupler as in claim 15, 16 or 17 in which the secondary fibres are equidistantly disposed about the central fibre.
Claim 21
Dependent Claim
25 words
An optical coupler as in claim 30, 31 or 32 in which there are an even number of secondary fibres which are grouped in pairs.
References Cited (Backward Citations)
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EP0212954A2
Cited
JPS63115112A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-12-29 | 1996-06-29 | 1996-12-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-12-29 | 2000-06-29 | 2000-12-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-12-29 | 2004-06-29 | 2004-12-29 | $7700.00 | Window Closed / Lapsed |