US4746185A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical fibre couplers
Assignee: Individual
•
Filing: 1986-06-23
•
Granted: 1988-05-24
•
Expires: 2006-06-23
Abstract
Abstract Optical fibre couplers are formed by selectively etching the cladding layer of portions of the fibres forming the coupler to provide them with an undulating profile, converging a group of fibres so that the undulating profiles interlock, and fusing the interlocking portions without drawing the fibres, so as to form a fused coupling zone of blended core and cladding glass. The fused zone is inserted in a ferrule, or a cladding layer is applied having a numerical aperture selected to maintain a more or less constant numerical aperture through the coupler. Such couplers may be cut in half and the halves optically coupled to each other by applying lenses to the cut ends and inserting the halves from opposite directions into a housing containing refractive index matching fluid so that the focuses of the lenses coincide.
Inventors
- 👤 Ferrydon Shahidi-Hamedani
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 10:28
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/24; G02B6/26; G02B6/28; G02B6/2804; G02B6/2808; G02B6/245; G02B6/2856
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
96 words
An optical fibre coupler formed from fibres having a glass core and a glass cladding layer of lower refractive index, whrein the fibres coupled have portions with a greatly reduced thickness of cladding layer and untapered cores which converge into a coupling zone formed without drawing from glass of the cores and claddings of the fibres, blended by fusion so that glass in the coupling zone has a refractive index intermediate between that of the core and the cladding, and wherein means are provided peripherally directly surrounding the coupling zone to prevent escape of light therefrom.
Claim 2
Dependent Claim
96 words
An optical fibre coupler formed from fibres having a glass core and a glass cladding layer of lower refractive index, whrein the fibres coupled have portions with a greatly reduced thickness of cladding layer and untapered cores which converge into a coupling zone formed without drawing from glass of the cores and claddings of the fibres, blended by fusion so that glass in the coupling zone has a refractive index intermediate between that of the core and the cladding, and wherein means are provided peripherally directly surrounding the coupling zone to prevent escape of light therefrom.
Claim 3
Dependent Claim
51 words
A coupler according to claim 1, wherein the means to prevent escape of light is a layer of a transparent substance surrounding the coupling zone and having a refractive index which is lower than that of the coupling zone and selected to maintain a substantially constant numerical aperture through the coupler.
Claim 4
Dependent Claim
17 words
A coupler according to claim 1, wherein fibres converge into both ends of an integral coupling zone.
Claim 5
Dependent Claim
35 words
A coupler according to claim 1, wherein the fibres converge into one end of the coupling zone and the means to prevent escape of light comprises a ferrule surrounding the periphery of the coupling zone.
Claim 6
Dependent Claim
29 words
A coupler according to claim 4, wherein the ferrule supports a lens adjacent the other end of the coupling zone and coupled thereto by a refractive index matching fluid.
Claim 7
Dependent Claim
51 words
A coupler assembly comprising a housing defining a central chamber and opposed coaxial bores entering the chamber from opposite sides, the chamber being filled with refractive index matching fluid and the ferrules of couplers according to claim 5 being inserted in the bores so that their lenses have a common focus.
Claim 8
Independent Claim
150 words
A method of manufacturing couplers for optical fibres, comprising etching the cladding glass of fibres to be coupled along lengths of the fibres from which the coupling is to be formed so as to remove most of the cladding layers of the fibres, selectively increasing the intensity of etching in multiple spaced zones of the etched length so as to remove all the cladding glass from the core glass in those zones, bringing the fibres into general longitudinal alignment and positioning the fibres so that their selectively etched zones interengage to provide close abutment between the fibres in those zones, fusing these zones together, while holding the fibres to prevent drawing of their cores, so as to form a fused coupling zone in which the core and cladding glasses are blended, and directly surrounding the peripheral surface of the fused coupling zone with means to prevent loss of light therefrom.
Claim 9
Independent Claim
150 words
A method of manufacturing couplers for optical fibres, comprising etching the cladding glass of fibres to be coupled along lengths of the fibres from which the coupling is to be formed so as to remove most of the cladding layers of the fibres, selectively increasing the intensity of etching in multiple spaced zones of the etched length so as to remove all the cladding glass from the core glass in those zones, bringing the fibres into general longitudinal alignment and positioning the fibres so that their selectively etched zones interengage to provide close abutment between the fibres in those zones, fusing these zones together, while holding the fibres to prevent drawing of their cores, so as to form a fused coupling zone in which the core and cladding glasses are blended, and directly surrounding the peripheral surface of the fused coupling zone with means to prevent loss of light therefrom.
Claim 10
Dependent Claim
56 words
A method according to claim 7, wherein the intensity of etching is selectively increased in a plurality of longitudinally spaced zones along each fibre so as to provide the fibre with a substantially sinusoidally undulating exterior or profile, and the fibres are longitudinally positioned relative to one another so that the profiles of adjacent fibres interlock.
Claim 11
Dependent Claim
45 words
A method according to claim 8, wherein the intensity of etching is selectively increased in said spaced zones by passing streams of gas bubbles through a bath of etchant in which the fibres are immersed so as to impinge on said zones of the fibres.
Claim 12
Dependent Claim
33 words
A method according to claim 8, wherein the fibres are secured in position relative to each other in zones to either side of the portions to be fused, prior to the fusion operation.
Claim 13
Dependent Claim
11 words
A method according to claim 10, wherein the fibres are braided.
Claim 14
Dependent Claim
21 words
A method according to claim 10, wherein the fibres are secured to spaced supports to either side of the fusion zone.
Claim 15
Dependent Claim
38 words
A method according to claim 7, wherein the peripheral surface of the fused coupling zone is surrounded with a layer of transparent substance having a refractive index selected to maintain a substantially constant numerical aperture through the coupler.
Claim 16
Dependent Claim
36 words
A method according to claim 7, wherein the coupler is cut in two through the fused coupling zone to form two coupler units, and the fused coupling zone of each unit is bonded into a ferrule.
Claim 17
Dependent Claim
43 words
A method according to claim 4, wherein the ferrule supports a lens at its end adjacent the cut end of the unit, and including the step of introducing a refractive index matching fluid into the ferrule between the lens and the fused zone.
Claim 18
Dependent Claim
47 words
A method according to claim 15, including the step of moving the ferrules of two units into opposed bores in the wall of a hollow housing filled with refractive index matching fluid, so as to submerge the ferrules, so that the focal points of the lenses coincide.
References Cited (Backward Citations)
US3933455A
Cited
US3891302A
Cited
US3995935A
Cited
US4119362A
Cited
US4083625A
Cited
GB2023874A
Cited
US4400055A
Cited
US4449781A
Cited
JPS57186730A
Cited
EP0069054A2
Cited
US4566753A
Cited
US4632513A
Cited
JPS6086511A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-05-24 | 1991-11-23 | 1992-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-24 | 1995-11-23 | 1996-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-24 | 1999-11-23 | 2000-05-24 | $7700.00 | Window Closed / Lapsed |