Rare earth element-doped optical waveguide and process for producing the same
First Claim
1. A rare earth element-doped optical waveguide comprising:
- a substrate;
a cladding provided on the substrate;
a core waveguide provided in the cladding, the core waveguide being substantially rectangular in cross section with the width thereof greater than the thickness thereof; and
a rare earth element-doped layer provided in the core waveguide along a waveguiding direction, whereby good optical confinement is ensured in the width direction of the waveguide.
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Accused Products
Abstract
A core waveguide having a substantially rectangular cross section, with the width thereof greater than the thickness thereof, is provided in a cladding formed on a substrate, and a rare earth element-doped layer is provided in the core waveguide along the waveguiding direction of the waveguide. With the width of the core waveguide set greater than the thickness of the core waveguide, good optical confinement in the width direction of the waveguide is obtained, which enables light to be absorbed by the rare earth element-doped layer efficiently and concentratedly. It is thereby possible to achieve a marked improvement in the excitation efficiency of excitation power. Thus, an enhanced excitation efficiency is achieved with less addition of a rare earth element, and a high-gain optical amplification waveguide free of concentration extinction is provided.
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Citations
12 Claims
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1. A rare earth element-doped optical waveguide comprising:
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a substrate; a cladding provided on the substrate; a core waveguide provided in the cladding, the core waveguide being substantially rectangular in cross section with the width thereof greater than the thickness thereof; and a rare earth element-doped layer provided in the core waveguide along a waveguiding direction, whereby good optical confinement is ensured in the width direction of the waveguide. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A rare earth element-doped optical waveguide comprising:
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a substrate; a cladding provided on the substrate; and a core waveguide provided in the cladding, the core waveguide being substantially rectangular in cross section, the core waveguide including a first core waveguide doped with a rare earth element and a second core waveguide not doped with a rare earth element, the first core waveguide being substantially rectangular in cross section, the second core waveguide covering the first core waveguide. - View Dependent Claims (8, 9)
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10. A method of producing a rare earth element-doped optical waveguide comprising the steps of;
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providing a first cladding layer on a substrate; laminating on the first cladding layer alternately at least one core layer not doped with a rare earth element and at least another core layer doped with a rare earth element; forming on the first cladding layer a core waveguide having a rare earth element-doped layer and being substantially rectangular in cross section; and providing a second cladding layer so as to cover the entire surface of the core waveguide.
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11. The method of producing a rare earth element-doped optical waveguide comprising the steps of:
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providing a first core waveguide doped with a rare earth element and substantially rectangular in cross section on a substrate having a low refractive index; providing a core layer not doped with a rare earth element over the substrate so as to bury completely the first core waveguide therein; forming on the substrate a core waveguide including the first core waveguide and a rare earth element-undoped second core waveguide covering the first core waveguide; and providing a cladding layer so as to cover the entire surface of the core waveguide. - View Dependent Claims (12)
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Specification