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EP0454590A2
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EP
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Polyimide optical waveguide
Assignee: NTT Inc
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Filing: 1991-04-26
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Granted: —
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Expires: 2011-04-26
Abstract
Abstract An optical waveguide which has properties including low optical losses, facile fabrication, controllrable core - cladding refractive index ratio, and high heat resistance is provided. The optical waveguide for light transmission therethrough has a core (2) made of a polyimide obtained from at least one tetracarboxylic acid dianhydride and at least one diamine. The polyimide is (a) a polyimide homopolymer derived from a diamine represented by formula [I] as follows: <CHEM> (b) a polyimide copolymer derived from at least one diamine including the diamine represented by the formula [I]; or (c) a mixture of the polyimide homopolymers. <IMAGE>
Inventors
- 👤 Toru Matsuura
- 👤 Shiro Nishi
- 👤 Shigekuni Sasaki
- 👤 Toshihiro Ichino
- 👤 Fumio Yamamoto
- 👤 Shinji Ando
- 👤 Fusao Shimokawa
- 👤 Shinji Koike
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 15:35
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/10; G02B6/12; G02B6/122; G02B6/1221; C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/1039; C08G73/1067; C08L; C08L79/00; C08L79/04; C08L79/08; G02B2006/12035; G02B2006/12069; G02B2006/12076
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
79 words
An optical waveguide for light transmission therethrough having a core, wherein the core is made of a polyimide obtained from at least one tetracarboxylic acid dianhydride and at least one diamine, the polyimide being selected from the group consisting of (a) a polyimide homopolymer derived from a diamine represented by formula [I] as follows: (b) a polyimide copolymer derived from at least one diamine including the diamine represented by the formula [I]; (c) a mixture of the polyimide homopolymers.
Claim 2
Dependent Claim
62 words
An optical waveguide having a core for light transmission therethrough, wherein the core is made of a polyimide copolymer including at least two units represented by the formulae [II] and [III] as follows: wherein each of R₁ and R₂ is a tetravalent organic group selected from the group consisting of with the proviso that R₁ and R₂ are different from each other.
Claim 3
Independent Claim
228 words
A method for making an optical waveguide for light transmission, the optical waveguide having a substrate and at least two stacked layers, first and second layers, formed to cover the substrate, the method comprising the steps of: (a) preparing a substrate and at least two kinds of solutions, at least one of which being of a poly(amic acid) which is a precursor of a polyimide, the polyimide being selected from the group consisting of (1) a polyimide homopolymer derived from a diamine represented by formula [I] as follows: (2) a polyimide copolymer derived from at least one diamine including the diamine represented by the formula [I] ; (3) a mixture of the polyimide homopolymers; (b) forming a layer of a solution of said at least two kinds of solutions over the substrate; (c) subjecting the layer of the solution to heat treatment at a maximum temperature of not less than 350 °C to solidify the layer of the solution to form a first layer; (d) forming a layer of the other solution of said at least two kinds of solutions on the first layer, wherein the first layer is insoluble in the other solution; (e) subjecting the layer of the other solution to heat treatment at a maximum temperature of not less than 350 °C to solidify the layer of the other solution to form a second layer.
Claim 4
Independent Claim
222 words
A method for making an optical waveguide for light transmission, the optical waveguide having a substrate and at least two stacked layers, first and second layers, formed to cover the substrate, the method comprising the steps of: (a) preparing a substrate and at least two kinds of solutions, at least one of which being of a poly(amic acid) which is a precursor of a polyimide copolymer including at least two units represented by formulae [II] and [III] as follows: wherein each of R₁ and R₂ is a tetravalent organic group selected from the group consisting of with the proviso that R₁ and R₂ are different from each other; (b) forming a layer of a solution of said at least two kinds of solutions over the substrate; (c) subjecting the layer of the solution to heat treatment at a maximum temperature of not less than 350 °C to solidify the layer of the solution to form a first layer; (d) forming a layer of the other solution of said at least two kinds of solutions on the first layer, wherein the first layer is insoluble in the other solution; (e) subjecting the layer of the other solution to heat treatment at a maximum temperature of not less than 350 °C to solidify the layer of the other solution to form a second layer.
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