EP0219096A2
Expired / Lapsed
EP
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Optical fiber star coupler and method of manufacturing the same
Assignee: Hitachi Ltd
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Filing: 1986-10-14
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Granted: —
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Expires: 2006-10-14
Abstract
Abstract While a middle part of a plastic optical fiber bundle in a lengthwise direction thereof is being heated, it is twisted, and it is pulled in axial directions of the bundle. A biconically tapered portion is formed at the middle part of the bundle by the twisting and the pulling. When the biconically tapered portion has been formed into a predetermined shape, the heating is stopped, and simultaneously, a gas is blown against an outer periphery of the biconically tapered portion so as to rapidly cool this tapered portion. The biconically tapered portion is solidified to the predetermined shape by the rapid cooling.
Inventors
- 👤 Katsuyuki Imoto
- 👤 Hirohisa Sano
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-25 16:55
CPC Classifications
B; B29; B29D; B29D11/00; B29D11/00663; G; G02; G02B; G02B6/00; G02B6/24; G02B6/26; G02B6/28; G02B6/2804; G02B6/2856
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
94 words
A plastic optical fiber star coupler comprising a bundle of plastic optical fibers each of which is constructed of a core of plastics and a cladding of plastics having a refractive index smaller than that of said core, a biconically tapered portion being formed at a substantially middle part of said bundle in such a way that said substantially middle part of said bundle is twisted in directions opposite to each other and that said plastic optical fibers are fused together and are pulled in opposite axial directions of said bundle while being heated.
Claim 2
Dependent Claim
94 words
A plastic optical fiber star coupler comprising a bundle of plastic optical fibers each of which is constructed of a core of plastics and a cladding of plastics having a refractive index smaller than that of said core, a biconically tapered portion being formed at a substantially middle part of said bundle in such a way that said substantially middle part of said bundle is twisted in directions opposite to each other and that said plastic optical fibers are fused together and are pulled in opposite axial directions of said bundle while being heated.
Claim 3
Dependent Claim
48 words
A plastic optical fiber star coupler according to claim 1, wherein an outer periphery of said bundle of plastic optical fibers including said biconically tapered portion is covered with a polymer which has a refractive index not greater than that of said cladding of said plastic optical fiber.
Claim 4
Dependent Claim
23 words
A plastic optical fiber star coupler according to claim 1, wherein at least said biconically tapered portion is received in a protective tube.
Claim 5
Dependent Claim
31 words
A plastic optical fiber star coupler according to claim 1, wherein the plastic optical fibers on each side of said biconically tapered portion are fastened to one another by a binder.
Claim 6
Dependent Claim
81 words
A plastic optical fiber star coupler according to claim 1, wherein each of said plastic optical fibers has in a substantially middle part thereof a waist portion whose diameter gradually decreases relative to a diameter of both end parts of said each fiber, the waist portions of the respective plastic optical fibers are twisted in directions opposite to each other, and the plastic optical fibers on each side of the twisted waist portions have tapered shapes substantially equal to each other.
Claim 7
Dependent Claim
35 words
A plastic optical fiber star coupler according to claim 5, wherein a diameter of a finest part of said waist part is not smaller than 50 % of the diameter of said both end parts.
Claim 8
Independent Claim
70 words
A method of manufacturing a plastic optical fiber star coupler comprising the steps of twisting and pulling a bundle of plastic optical fibers while heating the vicinity of a middle part of the fiber bundle, thereby to form a biconically tapered portion; and blowing a gas against an outer peripheral surface of said biconically tapered portion when a desired shape has been attained, thereby to cool said biconically tapered portion.
Claim 9
Independent Claim
70 words
A method of manufacturing a plastic optical fiber star coupler comprising the steps of twisting and pulling a bundle of plastic optical fibers while heating the vicinity of a middle part of the fiber bundle, thereby to form a biconically tapered portion; and blowing a gas against an outer peripheral surface of said biconically tapered portion when a desired shape has been attained, thereby to cool said biconically tapered portion.
Claim 10
Dependent Claim
54 words
A plastic optical fiber star coupler according to claim 7, wherein light is put into any fiber on an input side of the optical fiber bundle, emergent lights from the fibers on an output side are detected by optical detectors, and said gas is blown when respective emergent light intensities have become substantially equal.
Claim 11
Dependent Claim
27 words
A method of manufacturing a plastic optical fiber star coupler according to claim 7, wherein the heating is stopped substantially simultaneously with the blowing of said gas.
Claim 12
Dependent Claim
31 words
A method of manufacturing a plastic optical fiber star coupler according to claim 7, wherein the heating is conducted with a burner which uses a combustible gas containing no oxidizing gas.
Claim 13
Dependent Claim
32 words
A method of manufacturing a plastic optical fiber star coupler according to claim 7, wherein said bundle of plastic optical fibers is indirectly heated through a glass plate or a glass tube.
Claim 14
Independent Claim
67 words
A method of manufacturing a plastic optical fiber star coupler comprising the steps of depositing a solvent compatible with plastic optical fibers onto an outer peripheral surface of each of the optical fibers of an optical fiber bundle or onto an outer peripheral surface of said bundle; and heating, twisting and pulling the solvent-deposited part of said optical fiber bundle, thereby to form a biconically tapered portion.
Claim 15
Independent Claim
67 words
A method of manufacturing a plastic optical fiber star coupler comprising the steps of depositing a solvent compatible with plastic optical fibers onto an outer peripheral surface of each of the optical fibers of an optical fiber bundle or onto an outer peripheral surface of said bundle; and heating, twisting and pulling the solvent-deposited part of said optical fiber bundle, thereby to form a biconically tapered portion.
Claim 16
Dependent Claim
33 words
A method of manufacturing a plastic optical fiber star coupler according to claim 12, further comprising the step of twisting said optical fiber bundle in advance of the heating of said fiber bundle.
Claim 17
Dependent Claim
45 words
A method of manufacturing a plastic optical fiber star coupler according to claim 12, wherein said solvent contains a dopant which diffuses from an outer peripheral surface of a cladding of said optical fiber into said cladding and raises a refractive index of said cladding.
Claim 18
Dependent Claim
51 words
A method of manufacturing a plastic optical fiber star coupler according to claim 12, further comprising the step of covering an outer periphery of said optical fiber bundle including said biconically tapered portion, with a polymer which has a refractive index not higher than that of the fiber bundle outer periphery.
Claim 19
Dependent Claim
32 words
A method of manufacturing a plastic optical fiber star coupler according to claim 12, wherein said solvent contains a depressor which depresses dissolution of the outer peripheral surface of said optical fiber.
Claim 20
Dependent Claim
31 words
A method of manufacturing a plastic optical fiber star coupler according to claim 12, wherein an atmosphere during the heating of said fiber bundle is held at an inactive gas atmosphere.
Claim 21
Independent Claim
55 words
A method of manufacturing an optical fiber star coupler comprising the steps of forming a tapered waist porticn in a middle part of each of a plurality of optical fibers; bundling said plurality of optical fibers respectively formed with the waist portions; and twisting said waist portions of the bundled optical fibers while heating them.
Claim 22
Independent Claim
55 words
A method of manufacturing an optical fiber star coupler comprising the steps of forming a tapered waist porticn in a middle part of each of a plurality of optical fibers; bundling said plurality of optical fibers respectively formed with the waist portions; and twisting said waist portions of the bundled optical fibers while heating them.
Claim 23
Dependent Claim
34 words
A method of manufacturing an optical fiber star coupler according to claim 18, further comprising the step of pulling said waist portions in axial directions of said optical fibers after twisting said waist portions.
Claim 24
Dependent Claim
42 words
A method of manufacturing an optical fiber star coupler according to claim 18, wherein at the step of twisting said waist portions, said waist portions are pulled in axial directions of said optical fibers simultaneously with the twisting of said waist portions.
Claim 25
Dependent Claim
73 words
A method of manufacturing an optical fiber star coupler according to claim 18, wherein said tapered waist portion is formed by pulling the middle part of said each optical fiber in axial directions thereof while heating said middle part so that a diameter of a finest part of said waist portion may not become smaller than 50 % of a diameter of any part of said optical fiber other than said waist portion.
Claim 26
Dependent Claim
35 words
A method of manufacturing an optical fiber star coupler according to claim 18, further comprising the step of mounting a protective tube which covers at least the twisted waist portions, on said optical fiber bundle.
References Cited (Backward Citations)
No citation records indexed.
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