EP0340042A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Connecting optical waveguides
Assignee: British Telecommunications PLC
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Filing: 1989-04-28
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Granted: —
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Expires: 2009-04-28
Abstract
Abstract A method of splicing optical fibres in described in which at least one of the fibres has a high numerical aperture (NA) and the two fibres have different mode spot sizes. The method comprises fusing the ends of the fibres together with their cores in alignment and heating the fused junction between the fibres so as to cause dopant to migrate out of the core. The heating step is carried out for a time sufficient to achieve a predetermined level of matching between propagation modes in the two fibres.
Inventors
- 👤 David Stewart Forrester
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-26 13:28
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/24; G02B6/255; G02B6/2551; G02B6/2552; G02B6/26; G02B6/262; G02B6/42; G02B6/4201; G02B6/4202; G02B6/4203
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
89 words
A method of connecting optical waveguides having different refractive index profiles and at least one of the waveguides having a high numerical aperture (NA), the method comprising fusing the ends of the waveguides together with their cores in alignment and subsequently heating the fused junction between the waveguides so as to cause dopant to migrate out of the core of the high-NA waveguide, the heating step being carried out for a time sufficient to achieve a predetermined level of matching between the mode spot sizes in the two waveguides.
Claim 2
Independent Claim
89 words
A method of connecting optical waveguides having different refractive index profiles and at least one of the waveguides having a high numerical aperture (NA), the method comprising fusing the ends of the waveguides together with their cores in alignment and subsequently heating the fused junction between the waveguides so as to cause dopant to migrate out of the core of the high-NA waveguide, the heating step being carried out for a time sufficient to achieve a predetermined level of matching between the mode spot sizes in the two waveguides.
Claim 3
Dependent Claim
20 words
A method according to claim 1, wherein the heating step is carried out for a time not exceeding 30 seconds.
Claim 4
Dependent Claim
23 words
A method according to claim 1 or claim 2, wherein the fused function is heated to at least 1400°C during the heating step.
Claim 5
Independent Claim
22 words
A method according to any of the preceding claims, wherein the heating step is carried out until propagation losses reach a minimum.
Claim 6
Independent Claim
38 words
A method according to any of the preceding claims, wherein the heating step is carried until propagation losses have been reduced by at least 1dB over the losses occuring when the waveguides are butted together but not fused.
Claim 7
Independent Claim
19 words
A method according to any of the preceding claims, further comprising monitoring the propagation losses during the heating step.
Claim 8
Independent Claim
21 words
A method according to any of the preceding claims, wherein the numerical aperture of the high-NA waveguide is at least 0.15.
Claim 9
Dependent Claim
21 words
A method according to claim 7, wherein the numerical aperture of the high-NA waveguide lies in the range 0.15 to 0.3.
Claim 10
Independent Claim
15 words
A method according to any of the preceding claims, wherein the waveguides comprise optical fibres.
Claim 11
Independent Claim
16 words
A method of connecting optical waveguides substantially as hereinbefore described with reference to the accompanying drawings.
Claim 12
Independent Claim
16 words
A method of connecting optical waveguides substantially as hereinbefore described with reference to the accompanying drawings.
Claim 13
Dependent Claim
12 words
A high-NA optical fibre fused end to end with another optical fibre.
Claim 14
Dependent Claim
12 words
A high-NA optical fibre fused end to end with another optical fibre.
Claim 15
Dependent Claim
18 words
A combination according to claim 11, wherein the another optical fibre does not have a high numerical aperture.
Claim 16
Dependent Claim
20 words
A combination as claimed in claim 12 in which the high NA fibre is optically coupled to an optical source.
Claim 17
Dependent Claim
16 words
A combination as claimed in claim 13 in which the optical source is a semiconductor laser.
References Cited (Backward Citations)
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