US4989939A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coupler for optical fibers
Assignee: Imperial Chemical Industries Ltd
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Filing: 1989-05-30
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Granted: 1991-02-05
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Expires: 2009-05-30
Abstract
Abstract A non-invasive optical coupling device comprises means to hold an optical fibre while bending it with a radius of curvature sufficiently small to cause light to leak through the cladding, and means to hold a tap fibre in a predetermined position to receive at least a portion of the light leaking from the main fibre. This device enables light sources, sensors and various other optical communications devices to be connected via tap fibres to ring main fibres and data buses, without degradation of the fibres to which the tap fibres are connected.
Inventors
- 👤 Eric R. Cox
- 👤 Philippe J. C. Leliaert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 13:13
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/24; G02B6/26; G02B6/28; G02B6/2804; G02B6/2852
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
308 words
A device for optically coupling a main optical fibre comprising a core surrounded by cladding of lower refractive index, and having a protective layer surrounding of the cladding, to at least one tap fibre having a light receptive portion in the form of an exposed end face, the device comprising means to hold an intermediate portion of the main fibre with cladding and protective layer intact and to conform it to a predetermined path which executed a bend having a radius of curvature sufficiently small to cause some of any light flowing through the main fibre to leak from the cladding around the outer surface of the bend, the holding means comprising means to hold the end portion of the tap fibre with its end portion adjacent the outer surface of the bend to receive a least a portion of the light leaking from the cladding around the outer surface of the bend, in which the means for holding the main fibre comprises a first assembly having a mating surface positioned with respect to said predetermined path such that the cladding on the outer surface of the bend in the main fibrelies flush with the mating surface, and the means for holding the tap fibre comprises a second assembly lockable against the mating surface in a predetermined position wherein the light receptive portion of the tap fibre is positioned to receive at least a portion of the light leaking from the cladding around the outer surface of the bend in the main fibre, and including a stripping blade fixed to the second assembly which blade can be slid along the mating surface to strip a portion of the protective layer from the outer surface of the bend which is proud of the mating surface to expose the cladding as the second assembly is moved to its lockable position.
Claim 2
Independent Claim
308 words
A device for optically coupling a main optical fibre comprising a core surrounded by cladding of lower refractive index, and having a protective layer surrounding of the cladding, to at least one tap fibre having a light receptive portion in the form of an exposed end face, the device comprising means to hold an intermediate portion of the main fibre with cladding and protective layer intact and to conform it to a predetermined path which executed a bend having a radius of curvature sufficiently small to cause some of any light flowing through the main fibre to leak from the cladding around the outer surface of the bend, the holding means comprising means to hold the end portion of the tap fibre with its end portion adjacent the outer surface of the bend to receive a least a portion of the light leaking from the cladding around the outer surface of the bend, in which the means for holding the main fibre comprises a first assembly having a mating surface positioned with respect to said predetermined path such that the cladding on the outer surface of the bend in the main fibrelies flush with the mating surface, and the means for holding the tap fibre comprises a second assembly lockable against the mating surface in a predetermined position wherein the light receptive portion of the tap fibre is positioned to receive at least a portion of the light leaking from the cladding around the outer surface of the bend in the main fibre, and including a stripping blade fixed to the second assembly which blade can be slid along the mating surface to strip a portion of the protective layer from the outer surface of the bend which is proud of the mating surface to expose the cladding as the second assembly is moved to its lockable position.
Claim 3
Dependent Claim
59 words
A device as claimed iun claim 1 wherein the second assembly is locked in the predetermined position by sliding it along the mating surface, the stripping blade being located ahead of the tap fibre in the direction of sliding whereby stripping of any protective layers proud of the mating surface is effected automatically when locking the two assemblies together.
Claim 4
Dependent Claim
63 words
A device as claimed in claim 1 comprising means to hold two tap fibres with their exposed and faces adjacent to the outer surface of the bend in the main fibre but positioned substantially symmetrically with respect to said bend thereby to enable each to receive light travelling along the main fibre in the opposite direction and that received by the other fibre.
Claim 5
Dependent Claim
29 words
A device as claimed in claim 1 wherein the exposed end face is set out at an angle 15°-35° to the main axis of the tap fibre it terminates.
References Cited (Backward Citations)
US4601541A
Cited
US4676584A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-02-04 | 1994-08-06 | 1995-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-02-04 | 1998-08-06 | 1999-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-02-04 | 2002-08-06 | 2003-02-05 | $7700.00 | Window Closed / Lapsed |