US4785457A
Expired / Lapsed
US
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Heterostructure semiconductor laser
Assignee: Boeing North American Inc
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Filing: 1987-05-11
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Granted: 1988-11-15
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Expires: 2007-05-11
Abstract
Abstract The crystallographic plane-dependent, amphoteric nature of Si-doped AlGaAs is used to provide a low threshold semiconductor laser. An active layer of AlGaAs is sandwiched between an injection layer and a current confining layer of AlGaAs. The injection layer is doped to be n-type conductivity. The confining layer is amphoterically doped with Si to be n-type in a (100) plane and p-type in a (111)A plane. The resulting p-n junctions, heterostructure, and geometry provide the current and the optical confinement for the semiconductor laser.
Inventors
- 👤 Peter M. Asbeck
- 👤 David L. Miller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 12:30
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/20; H01S5/22; H01S5/223; H01S5/2238; H01S5/30; H01S5/305; H01S5/3077; H01S5/3081
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
133 words
In a semiconductor laser: an epitaxial active layer of a semiconductor; an epitaxial injection layer of a semiconductor on one side of the active layer; an epitaxial confinement layer of a semiconductor on the other side of the active layer having a dopant that provides a first conductivity in first crystallographic planes and an opposite conductivity in second crystallographic planes having a different orientation, the confinement layer having a first portion which lies within the first crystallographic planes and another portion which lies within the second crystallographic planes on both sides of the first portion whereby current across the active layer can be confined to the first portion by the change in conductivity type of the confinement layer; and means for making electrical contact to the injection layer and to the confinement layer.
Claim 2
Dependent Claim
133 words
In a semiconductor laser: an epitaxial active layer of a semiconductor; an epitaxial injection layer of a semiconductor on one side of the active layer; an epitaxial confinement layer of a semiconductor on the other side of the active layer having a dopant that provides a first conductivity in first crystallographic planes and an opposite conductivity in second crystallographic planes having a different orientation, the confinement layer having a first portion which lies within the first crystallographic planes and another portion which lies within the second crystallographic planes on both sides of the first portion whereby current across the active layer can be confined to the first portion by the change in conductivity type of the confinement layer; and means for making electrical contact to the injection layer and to the confinement layer.
Claim 3
Dependent Claim
17 words
The semiconductor laser as claimed in claim 1 including an epitaxial semiconductor substrate adjoining the injection layer.
Claim 4
Dependent Claim
17 words
The semiconductor laser as claimed in claim 1 including an epitaxial semiconductor substrate adjoining the confinement layer.
Claim 5
Dependent Claim
39 words
The semiconductor laser as claimed in claim 2 wherein the means for making electrical contact comprises an epitaxial cap layer on the confinement layer and a metal contact on the cap layer, and a metal contact on the substrate.
Claim 6
Dependent Claim
39 words
The semiconductor laser as claimed in claim 3 wherein the means for making electrical contact comprises an epitaxial cap layer on the confinement layer and a metal contact on the cap layer, and a metal contact on the substrate.
Claim 7
Dependent Claim
16 words
The semiconductor laser as claimed in claim 1 wherein the semiconductor is a III-V compound semiconductor.
Claim 8
Dependent Claim
13 words
The semiconductor laser as claimed in claim 6 wherein the dopant is Si.
Claim 9
Dependent Claim
13 words
The semiconductor laser as claimed in claim 6 wherein the dopant is Ge.
Claim 10
Dependent Claim
119 words
In a semiconductor laser: an epitaxial active layer of AlGaAs; an epitaxial injection layer of AlGaAs doped to be n-type conductivity on one side of the active layer; an epitaxial confining layer of AlGaAs on the other side of the active layer, the confining layer being amphoterically doped with Si and having an n-type conductivity portion in a (100) crystallographic plane and a p-type conductivity portion in a (111)A crystallographic plane, the n-type portion confining the p-type portion to a strip within the confining layer; and means for making electrical contact to the injection layer and to the confining layer, whereby current across the active layer can be confined by the p-type conductivity portion of the Si-doped confining layer.
Claim 11
Dependent Claim
119 words
In a semiconductor laser: an epitaxial active layer of AlGaAs; an epitaxial injection layer of AlGaAs doped to be n-type conductivity on one side of the active layer; an epitaxial confining layer of AlGaAs on the other side of the active layer, the confining layer being amphoterically doped with Si and having an n-type conductivity portion in a (100) crystallographic plane and a p-type conductivity portion in a (111)A crystallographic plane, the n-type portion confining the p-type portion to a strip within the confining layer; and means for making electrical contact to the injection layer and to the confining layer, whereby current across the active layer can be confined by the p-type conductivity portion of the Si-doped confining layer.
Claim 12
Dependent Claim
19 words
The semiconductor laser as claimed in claim 9 including an epitaxial GaAs substrate adjoining the n-type conductivity injection layer.
Claim 13
Dependent Claim
18 words
The semiconductor laser as claimed in claim 9 including a GaAs substrate adjoining the amphoterically Si-doped confining layer.
Claim 14
Dependent Claim
30 words
The semiconductor laser as claimed in claim 10 including: an epitaxial current blocking layer on the amphoterically Si-doped confining layer; and an epitaxial cap layer on the current blocking layer.
Claim 15
Dependent Claim
36 words
The semiconductor laser as claimed in claim 12 wherein the current blocking layer comprises a p-type conductivity layer of AlGaAs and a second AlGaAs layer amphoterically doped with Si on the p-type conductivity layer of AlGaAs.
Claim 16
Dependent Claim
44 words
The semiconductor laser as claimed in claim 12 wherein the cap layer comprises a p + -type conductivity layer of GaAs, and wherein the means for making electrical contact comprises a metal contact on the cap layer and a metal contact on the substrate.
Claim 17
Dependent Claim
18 words
The semiconductor laser as claimed in claim 9 wherein the active layer comprises a GaAs/AlGaAs multi-quantum well structure.
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) | 1991-11-15 | 1992-05-16 | 1992-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-11-15 | 1996-05-16 | 1996-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-11-15 | 2000-05-16 | 2000-11-15 | $7700.00 | Window Closed / Lapsed |