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US 4,904,037 AGranted
Waveguide type optical device with thermal compensation layers
AssigneeHitachi, Ltd.
InventorsKatsuyuki Imoto, Hirohisa Sano, Yasuo Hira
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Abstract
A waveguide type optical device in which a waveguide layer for propagating light is provided on the front surface of a substrate, and a compensation layer having a coefficient of thermal expansion substantially equal to that of the waveguide layer formed on the front surface is provided on the rear surface of the substrate.
Claims5
A waveguide type optical device comprising:
- a substrate;
- a buffer layer formed on a front surface of the substrate, having a coefficient of thermal expansion considerably different from that of the substrate;
- a core layer formed on the buffer layer, having a coefficient of thermal expansion smaller than that of the buffer layer;
- a cladding layer formed on at least said core layer, having a coefficient of thermal expansion larger than that of said core layer;
- and
- a first compensation layer formed on a rear surface of the substrate, having a coefficient of thermal expansion substantially equal to that of said buffer layer.
3 more elements
A waveguide type optical device comprising:
- a substrate;
- a buffer layer formed on a front surface of said substrate, having a coefficient of thermal expansion considerably different from that of said substrate;
- a core layer disposed in said buffer layer, having a coefficient of thermal expansion smaller than that of said buffer layer;
- and
- a compensation layer formed on a rear surface of said substrate, having a coefficient of thermal expansion substantially equal to that of said buffer layer.
2 more elements
Dependencies are inferred from the claim text.