Patent EP0304709A2 successfully refreshed from Google Patents.
EP0304709A2
Expired / Lapsed
EP
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Waveguide type optical device
Assignee: Hitachi Ltd
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Filing: 1988-08-05
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Granted: —
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Expires: 2008-08-05
Abstract
Abstract A waveguide type optical device in which a waveguide layer (2...4) for propagating light is provided on the front surface of a substrate (1), and a compensation layer (5, 6) having a coefficient of thermal expansion substantially equal to that of the waveguide layer (2...4) formed on the front surface is provided on the rear surface of the substrate (1).
Inventors
- 👤 Imoto Katsuyuki
- 👤 Sano Hirohisa
- 👤 Hira Yasuo
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-28 03:24
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/10; G02B6/12; G02B6/12007; G02B6/122; G02B6/126; G02B2006/12166; G02B2006/12169
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
62 words
A waveguide type optical device comprising a substrate (1), a waveguide layer (2...4) which propagates light and which is provided on a front surface of said substrate (1), and a compensation layer (5, 6) which has a coefficient of thermal expansion substantially equal to that of said waveguide layer (2...4) and which is provided on a rear surface of said substrate (1).
Claim 2
Dependent Claim
62 words
A waveguide type optical device comprising a substrate (1), a waveguide layer (2...4) which propagates light and which is provided on a front surface of said substrate (1), and a compensation layer (5, 6) which has a coefficient of thermal expansion substantially equal to that of said waveguide layer (2...4) and which is provided on a rear surface of said substrate (1).
Claim 3
Dependent Claim
18 words
The device of claim 1, wherein said compensation layer (5, 6) is formed into a plurality of layers.
Claim 4
Independent Claim
54 words
The device of claims 1 or 2, wherein each of said layers (2...4, 5, 6) which are respectively formed on the front and rear surfaces of said substrate (1) is made of a glass film, a plastics film, a magnetic substance film, a crystal film, a metal film, or a combination of these films.
References Cited (Backward Citations)
No citation records indexed.
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