EP0254462A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Indium-clad fiber-optic polarizer
Assignee: Commscope Technologies AG
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Filing: 1987-07-13
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Granted: —
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Expires: 2007-07-13
Abstract
Abstract A fiber-optic polarizer comprising an optical fiber 10 having a polarization-holding core 21 and cladding 22 with different refractive indices and forming a single-mode guiding region, the guiding region being offset from the center of gravity of the fiber section and located sufficiently close to the surface 24 of one side of the fiber 10, along a selected length of the fiber, to expose the evanescent field of the guiding region at the surface 24 of the one side to allow coupling to a contiguous medium, the outer surface 24 of the fiber having a non-circular cross-section with a predetermined geometric relationship to the guiding region and a pair of orthogonal polarization axes therein so that the location of the guiding region and the orientation of the axes can be ascertained from the geometry of the outer surface, and a coating 25 of indium on at least the one side 24 of the fiber where the evanescent field is exposed so that light waves having undesired polarizations are attenuated by the indium coating.
Inventors
- 👤 Richard B. Dyott
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 06:45
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/10; G02B6/105
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
177 words
A fiber-optic polarizer comprising an optical fiber 10 having a polarization-holding core 21 and cladding 22 with different refractive indices and forming a single-mode guiding region, said guiding region being offset from the center of gravity of the fiber section and located sufficiently close to the surface 24 of one side of the fiber 10, along a selected length of the fiber 10, to expose the evanescent field of the guiding region at the surface 24 of said one side to allow coupling to a contiguous medium, the outer surface of the fiber 10 having a non-circular cross-section with a predetermined geometric relationship to said guiding region and a pair of orthogonal polarization axes therein so that the location of said guiding region and the orientation of said axes can be ascertained from the geometry of said outer surface, and characterised by a coating 25 of indium on at least said one side of the fiber 10 where said evanescent field is exposed so that light waves having undesired polarizations are attenuated by said indium coating 25.
Claim 2
Dependent Claim
177 words
A fiber-optic polarizer comprising an optical fiber 10 having a polarization-holding core 21 and cladding 22 with different refractive indices and forming a single-mode guiding region, said guiding region being offset from the center of gravity of the fiber section and located sufficiently close to the surface 24 of one side of the fiber 10, along a selected length of the fiber 10, to expose the evanescent field of the guiding region at the surface 24 of said one side to allow coupling to a contiguous medium, the outer surface of the fiber 10 having a non-circular cross-section with a predetermined geometric relationship to said guiding region and a pair of orthogonal polarization axes therein so that the location of said guiding region and the orientation of said axes can be ascertained from the geometry of said outer surface, and characterised by a coating 25 of indium on at least said one side of the fiber 10 where said evanescent field is exposed so that light waves having undesired polarizations are attenuated by said indium coating 25.
Claim 3
Dependent Claim
40 words
A fiber-optic polarizer as claimed in claim 1 characterised in that the light waves that are attenuated have a field perpendicular to the interface between said indium coating 25 and the fiber surface 24 where said evanescent field is exposed.
Claim 4
Dependent Claim
42 words
A fiber-optic polarizer as claimed in either preceding claim characterised in that said core 21 has a non-circular cross-section defining two transverse orthogonal axes 2a, 2b which, in combination with said different refractive indices, de-couple waves polarized along said axes 2a, 2b.
Claim 5
Dependent Claim
60 words
A fiber-optic polarizer as claimed in any preceding claim characterised in that said core 21 has an elliptical cross-section, the outer surface of said fiber 10 has at least one flat surface 24 which is parallel to one of the transverse axes 2a,2b of said elliptical core 21, and said coating 25 of indium is on said flat surface 24.
Claim 6
Dependent Claim
19 words
A fiber-optic polarizer as claimed in any preceding claim characterised in that said indium coating 25 is elemental indium.
Claim 7
Independent Claim
190 words
A method of forming a fiber-optic polarizer comprising the steps of forming an optical fiber having a polarization-holding core and cladding with different refractive indices and forming a single-mode guiding region, said guiding region being offset from the center of gravity of the fiber and located sufficiently close to the surface of one side of the fiber, along a selected length of the fiber, to expose the evanescent field of the guiding region at the surface of said one side to allow coupling to a contiguous medium, the outer surface of the fiber having a non-circular cross section with a predetermined geometric relationship to said guiding region and a pair of orthogonal polarization axes therein so that the location of said guiding region and the orientation of said axes can be ascertained from the geometry of said outer surface, and characterised by coating at least one side of the fiber, where said evanescent field is exposed, with molten indium at a temperature sufficiently low that it does not melt the fiber, and then cooling the molten indium on the fiber to form a solid indium coating bonded to the fiber.
Claim 8
Independent Claim
190 words
A method of forming a fiber-optic polarizer comprising the steps of forming an optical fiber having a polarization-holding core and cladding with different refractive indices and forming a single-mode guiding region, said guiding region being offset from the center of gravity of the fiber and located sufficiently close to the surface of one side of the fiber, along a selected length of the fiber, to expose the evanescent field of the guiding region at the surface of said one side to allow coupling to a contiguous medium, the outer surface of the fiber having a non-circular cross section with a predetermined geometric relationship to said guiding region and a pair of orthogonal polarization axes therein so that the location of said guiding region and the orientation of said axes can be ascertained from the geometry of said outer surface, and characterised by coating at least one side of the fiber, where said evanescent field is exposed, with molten indium at a temperature sufficiently low that it does not melt the fiber, and then cooling the molten indium on the fiber to form a solid indium coating bonded to the fiber.
Claim 9
Dependent Claim
21 words
The method as claimed in claim 6 characterised in that said coating step is carried out in the presence of oxygen.
Claim 10
Dependent Claim
38 words
The method as claimed in claim 6 or claim 7 characterised in that said core has a non-circular cross-section defining two transverse orthogonal axes which, in combination with said different refractive indices, de-couple waves polarized along said axes.
Claim 11
Dependent Claim
51 words
The method as claimed in claim 6 characterised in that said core has an elliptical cross-section, the outer surface of said fiber has at least one flat surface which is parallel to one of the transverse axes of said elliptical core, and said coating of indium is on said flat surface.
Claim 12
Dependent Claim
16 words
The method as claimed in claim 6 characterized in that said indium coating is elemental indium.
References Cited (Backward Citations)
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