US4986627A
Expired / Lapsed
US
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Method for connecting optical fibres without Fresnel reflection and system thus detained, variable optical attenuator and system using this attenuator to measure the effect of the reflection coeficient on an optical line
Assignee: France Telecom R&D SA
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Filing: 1989-06-08
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Granted: 1991-01-22
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Expires: 2009-06-08
Abstract
Abstract This invention concerns a method for connecting optical fibres, comprising stages consisting in (i) effecting a controlled rough polishing of the interface (5) of the fibres (1) to be connected, (ii) steeping the ends of the fibres (1) in a concentrated solution hydrofluoric acid and (iii) aligning then connecting the fibres (1) using an index matching material (FIG. 4). The invention also concerns a variable optical attenuator and a system using this attenuator to measure the effect of the reflection coefficient on an optical line.
Inventors
- 👤 Daniel Boscher
- 👤 Rene Le Marer
- 👤 Gabrielle Perrin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 17:15
CPC Classifications
G; G01; G01M; G01M11/00; G01M11/30; G01M11/31; G02; G02B; G02B6/00; G02B6/24; G02B6/255; G02B6/2551; G02B6/26; G02B6/262; G02B6/264; G02B6/266; G02B6/36; G02B6/38; G02B6/3807; G02B6/381; G02B6/3818; G02B6/382; G02B6/3833; G02B6/3834; G02B6/3843; G02B6/3863
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
58 words
Method for connecting optical fibres characterised in that it comprises stages consisting of: (i) effecting a controlled rough polishing of the interface (5) of the fibres (1) to be connected, (ii) steeping the ends of the fibres (1) in a concentrated solution of hydrofluoric acid, and (iii) aligning then connecting the fibres (1) using an index matching material.
Claim 2
Dependent Claim
58 words
Method for connecting optical fibres characterised in that it comprises stages consisting of: (i) effecting a controlled rough polishing of the interface (5) of the fibres (1) to be connected, (ii) steeping the ends of the fibres (1) in a concentrated solution of hydrofluoric acid, and (iii) aligning then connecting the fibres (1) using an index matching material.
Claim 3
Dependent Claim
25 words
Method according to claim 1 characterised in that the polishing operation (i) is effected with a polishing element with a grain size greater than 3μ.
Claim 4
Dependent Claim
26 words
Method according to claim 1, characterised in that the polishing operation (i) is effected with a polishing element with a grain size between 3 and 12μ.
Claim 5
Dependent Claim
32 words
Method according to claim 1, characterised in that the operation (ii) consists in steeping the ends of the fibres in a solution of hydrofluoric acid for a period more than 20 seconds.
Claim 6
Dependent Claim
32 words
Method according to claim 1, characterised in that operation (ii) consists in steeping the ends of the fibres in a solution of hydrofluoric acid for a period between 20 and 30 seconds.
Claim 7
Dependent Claim
21 words
Method according to claim 1, characterised in that the hydrofluoric acid used in stage (ii) has a concentration of around 40%.
Claim 8
Dependent Claim
16 words
Method according to claim 1, characterised in that the index matching material (6) is an oil.
Claim 9
Dependent Claim
18 words
Method according to claim 1, characterised in that the index matching material (6) is a UV polymerisable resin.
Claim 10
Dependent Claim
86 words
Method for connecting optical fibers comprising the steps of (i) effecting a controlled rough polishing of end faces of the fibers to be connected with a polishing element having a grain size between 3 μm and 12 μm, (ii) steeping the polished ends of the fibers in a solution of hydrofluoric acid having a concentration about 40% for a period between 20 and 30 seconds to generate cracks of an average width of 1 to 2 μm on the end faces of the optical fibers, and
Claim 11
Dependent Claim
86 words
Method for connecting optical fibers comprising the steps of (i) effecting a controlled rough polishing of end faces of the fibers to be connected with a polishing element having a grain size between 3 μm and 12 μm, (ii) steeping the polished ends of the fibers in a solution of hydrofluoric acid having a concentration about 40% for a period between 20 and 30 seconds to generate cracks of an average width of 1 to 2 μm on the end faces of the optical fibers, and
Claim 12
Dependent Claim
11 words
(iii) aligning and connecting the fibers using an index matching material.
Claim 13
Dependent Claim
11 words
(iii) aligning and connecting the fibers using an index matching material.
Claim 14
Dependent Claim
68 words
Optical system comprising two optical fibres which have been rough polished, steeped in a concentrated solution of hydrofluoric acid and then aligned and connected with the use of an index matching material, characterised in that the interface 5 of the optical fibres has cracks of an average width of 1 to 2μ generated while said fibers were being steeped in said concentrated solution in the hydrofluoric acid solution.
Claim 15
Dependent Claim
68 words
Optical system comprising two optical fibres which have been rough polished, steeped in a concentrated solution of hydrofluoric acid and then aligned and connected with the use of an index matching material, characterised in that the interface 5 of the optical fibres has cracks of an average width of 1 to 2μ generated while said fibers were being steeped in said concentrated solution in the hydrofluoric acid solution.
Claim 16
Dependent Claim
105 words
Variable optical attenuator, characterised in that it comprises two optical fibres (40, 50) one end of each of which is previously treated by controlled rough polishing then steeped in a concentrated solution of hydrofluoric acid to prevent any Fresnel reflection, two supporting elements (20, 30) capable of controlled relative movement and adapted to receive and support respectively said fibres (40, 50) in such a way that the treated ends (42, 52) of said fibres are positioned facing each other, with their axes (23, 33) parallel, but with an overlap area which varies as a function of the relative position of said supporting elements (20, 30).
Claim 17
Dependent Claim
105 words
Variable optical attenuator, characterised in that it comprises two optical fibres (40, 50) one end of each of which is previously treated by controlled rough polishing then steeped in a concentrated solution of hydrofluoric acid to prevent any Fresnel reflection, two supporting elements (20, 30) capable of controlled relative movement and adapted to receive and support respectively said fibres (40, 50) in such a way that the treated ends (42, 52) of said fibres are positioned facing each other, with their axes (23, 33) parallel, but with an overlap area which varies as a function of the relative position of said supporting elements (20, 30).
Claim 18
Dependent Claim
39 words
Variable optical attenuator according to claim 11, characterised in that one of the supporting elements (30) consists of a ferrule with an outer cylindrical casing bored with an eccentric hole (32) capable of receiving one of the fibres (50).
Claim 19
Dependent Claim
22 words
Variable optical attenuator according to claim 12, characterised in that the ferrule (30) is associated with a rotating drive element (60, 62).
Claim 20
Dependent Claim
35 words
Variable optical attenuator according to claim 13, characterised in that the rotating drive element comprises a journal (60) which carries a toric rubber belt (62) which lies on the external periphery of the ferrule (30).
Claim 21
Dependent Claim
60 words
Variable optical attenuator according to claim 11, characterised in that the two supporting elements (20, 30) are formed from identical ferrules with a cylindrical outer casing bored with an eccentric hole (22, 32) capable of receiving one of the fibres (40, 50), one of the ferrules (20) being fixed while the other (30) is guided in rotation about its axis.
Claim 22
Dependent Claim
22 words
Variable optical attenuator according to claim 15, characterised in that each of said ferules (20, 30) is made of a ceramic material.
Claim 23
Dependent Claim
42 words
Variable optical attenuator according to claim 11, characterised in that it comprises a base (10) including a V-shaped groove (12) which receives two ferrules (20, 30) bored with eccentric holes (22, 32), each of which receives one of the fibres (40, 50).
Claim 24
Dependent Claim
19 words
Variable optical attenuator according to claim 17 characterised in that the base (10) is made of a ceramic material.
Claim 25
Dependent Claim
87 words
System for measuring the effect of the reflection coefficient on an optical line, characterised in that it comprises a coupler (110) with two branches (111, 114) of known transfer ratio, having one end (112) of the first branch (111) coupled to an emitting means (110) while the second branch (114) of the coupler has one end (116) coupled through the intermediary of an optical attenuator in accordance with claim 11 to a reflecting means (130) and its second end (115) coupled to an optical detecting means (140).
Claim 26
Dependent Claim
20 words
System according to claim 19, characterised in that the coupler (110) is a coupler with a transfer ratio of 50/50.
Claim 27
Dependent Claim
24 words
System according to claim 19, characterised in that the second end (113) of the first branch (111) is linked to a transmission line (150).
Claim 28
Dependent Claim
22 words
System according to claim 19, characterised in that it comprises at least one connector (102, 151, 160) formed from anti-reflection treated half-connectors.
Claim 29
Dependent Claim
36 words
System according to claim 22, characterised in that the half-connectors (103, 104, 152, 153, 161, 162) are treated by controlled rough polishing then steeped in a concentrated solution of hydrofluoric acid to avoid any Fresnel reflection.
References Cited (Backward Citations)
JPS5711313A
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JPS595216A
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US4783137A
Cited
JPS60175007A
Cited
EP0171271A2
Cited
JPS61102604A
Cited
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