Patent US4795225A successfully refreshed from Google Patents.
US4795225A
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US
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Semiconductor optical switch
Assignee: KDDI Corp
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Filing: 1988-01-13
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Granted: 1989-01-03
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Expires: 2008-01-13
Abstract
Abstract An optical switch is disclosed in which a switching section for switching the optical path of an incident light is formed in a region where two semiconductor optical waveguides cross each other. The switching section is composed of n-, i-, p-, i- and n-type semiconductor layers laminated in that order, each i-type layer being formed by a superlattice layer composed of a plurality of semiconductor thin films so that the i-type layer is higher in the effective refractive index and smaller in the effective energy gap than each n-type layer. The impurity concentrations of the n-, i-, p-, i-, and n-type layers and the thicknesses of the i-, p-, and i-type layers are determined so that the i-, p- and i-type layers are depleted in a thermal equilibrium state.
Inventors
- 👤 Kazuo Sakai
- 👤 Yuichi Matsushima
- 👤 Katsuyuki Utaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:32
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/29; G02F1/31; G02F1/313; G02F1/3137; G02F1/3138; B; B82; B82Y; B82Y20/00; G02F1/01; G02F1/015; G02F1/017; G02F1/01708; G02F1/0151; G02F1/0152
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
132 words
An optical switch in which a switching section for switching the optical path of an incident light is formed in a region where two semiconductor optical waveguides cross each other, characterized in: that the switching section is composed of n-, i-, p-, i- and n- type semiconductor layers laminated in that order, each i-type layer being formed by a superlattice layer composed of a plurality of semi-conductor thin films so that the i-type layer is higher in the effective refractive index and smaller in the effective energy gap than each n-type layer; and that the impurity concentrations of the n-, i-, p-, i-and n-type layers and the thicknesses of the i-, p- and i-type layers are determined so that the i-, p- and i-type layers are depleted in a thermal equilibrium state.
Claim 2
Dependent Claim
132 words
An optical switch in which a switching section for switching the optical path of an incident light is formed in a region where two semiconductor optical waveguides cross each other, characterized in: that the switching section is composed of n-, i-, p-, i- and n- type semiconductor layers laminated in that order, each i-type layer being formed by a superlattice layer composed of a plurality of semi-conductor thin films so that the i-type layer is higher in the effective refractive index and smaller in the effective energy gap than each n-type layer; and that the impurity concentrations of the n-, i-, p-, i-and n-type layers and the thicknesses of the i-, p- and i-type layers are determined so that the i-, p- and i-type layers are depleted in a thermal equilibrium state.
Claim 3
Dependent Claim
38 words
An optical switch according to claim 1, in which each of said semiconductor thin films forming the superlattice layer has a thickness less than 300 Å and an impurity concentration of less than 10 16 cm -3 .
Claim 4
Dependent Claim
32 words
An optical switch according to claim 1, in which the p-type semiconductor layer has a thickness less than 500 Å and an impurity concentration of more than 10 17 cm -3 .
Claim 5
Dependent Claim
27 words
An optical switch according to claim 1, in which each of said n-type semiconductor layers has an impurity concentration of more than 10 17 cm -3 .
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-01-03 | 1992-07-04 | 1993-01-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-01-03 | 1996-07-04 | 1997-01-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-01-03 | 2000-07-04 | 2001-01-03 | $7700.00 | Window Closed / Lapsed |