Patent US4811353A successfully refreshed from Google Patents.
US4811353A
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US
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Semiconductor optical modulator
Assignee: KDDI Corp
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Filing: 1987-02-18
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Granted: 1989-03-07
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Expires: 2007-02-18
Abstract
Abstract A semiconductor optical modulator is disclosed which is capable of high-speed modulation without the necessity of increasing the modulating voltage. The present invention has its feature in that the carrier density of the clad layer adjoining the optical waveguide layer 3 is gradually raised toward the p-n junction or Schottky junction, thereby increasing the width of the depletion layer to decrease the junction capacitance.
Inventors
- 👤 Yukio Noda
- 👤 Masatoshi Suzuki
- 👤 Yukitoshi Kushiro
- 👤 Shigeyuki Akiba
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 16:22
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/10; H01S5/16; G; G02; G02F; G02F1/00; G02F1/01; G02F1/015; G02F1/025; H01S5/02; H01S5/026; H01S5/0265; H01S5/12; H01S5/164; H01S5/168
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
75 words
In a semiconductor optical modulator having a substrate, a clad layer having a carrier density gradient and composed of at least one layer formed on the substrate, an optical waveguide layer on the clad layer for controlling light, semiconductor means for defining a p-n junction, said means being disposed on the optical waveguide layer, and the clad layer having a carrier density gradually decreasing as distance away from the optical waveguide toward the substrate increases.
Claim 2
Dependent Claim
75 words
In a semiconductor optical modulator having a substrate, a clad layer having a carrier density gradient and composed of at least one layer formed on the substrate, an optical waveguide layer on the clad layer for controlling light, semiconductor means for defining a p-n junction, said means being disposed on the optical waveguide layer, and the clad layer having a carrier density gradually decreasing as distance away from the optical waveguide toward the substrate increases.
Claim 3
Dependent Claim
25 words
In a semiconductor optical modulator according to claim 1, in which the carrier density of the clad layer continuously decreases progressively as said distance increases.
Claim 4
Dependent Claim
20 words
In a semiconductor optical modulator according to claim 1, in which the carrier density of the clad layer discretely decreases.
Claim 5
Dependent Claim
31 words
In a semiconductor optical optical modulator according to claim 1, in which the carrier density of the clad layer decreases from 10 14 cm -3 to 5×10 15 cm -3 .
Claim 6
Dependent Claim
21 words
In a semiconductor optical modulator according to claim 1, in which the thickness of the clad layer is about 1.4 μm.
Claim 7
Dependent Claim
41 words
In a semiconductor optical modulator according to claim 1, including a distributed feedback semiconductor laser formed therewith in a monolithic integration therewith, and the substrate and clad layer are common to the semiconductor optical modulator and the distributed feedback semiconductor laser.
Claim 8
Dependent Claim
74 words
In a semiconductor optical modulator having a substrate, a clad layer having a carrier density gradient and composed of at least one layer formed on the substrate, an optical waveguide layer on the clad layer for controlling light, means for defining a Schottky junction, said means being disposed on the optical waveguide layer, and the clad layer having a carrier density gradually decreasing as distance away from the optical waveguide toward the substrate increases.
Claim 9
Dependent Claim
74 words
In a semiconductor optical modulator having a substrate, a clad layer having a carrier density gradient and composed of at least one layer formed on the substrate, an optical waveguide layer on the clad layer for controlling light, means for defining a Schottky junction, said means being disposed on the optical waveguide layer, and the clad layer having a carrier density gradually decreasing as distance away from the optical waveguide toward the substrate increases.
Claim 10
Dependent Claim
24 words
In a semiconductor optical modulator according to claim 7, in the carrier density of the clad layer continuously decreases progressively as said distance increases.
Claim 11
Dependent Claim
20 words
In a semiconductor optical modulator according to claim 7, in which the carrier density of the clad layer discretely decreases.
Claim 12
Dependent Claim
30 words
In a semiconductor optical modulator according to claim 7, in which the carrier density of the clad layer decreases from 10 14 cm -3 to 5×10 15 cm -3 .
Claim 13
Dependent Claim
21 words
In a semiconductor optical modulator according to claim 7, in which the thickness of the clad layer is about 1.4 μm.
Claim 14
Dependent Claim
41 words
In a semiconductor optical modulator according to claim 7, including a distributed feedback semiconductor laser formed therewith in a monolithic integration therewith, and the substrate and clad layer are common to the semiconductor optical modulator and the distributed feedback semiconductor laser.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1992-03-06 | 1992-09-05 | 1993-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-06 | 1996-09-05 | 1997-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-06 | 2000-09-05 | 2001-03-07 | $7700.00 | Window Closed / Lapsed |