US4941148A
Expired / Lapsed
US
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Semiconductor laser element with a single longitudinal oscillation mode
Assignee: Sharp Corp
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Filing: 1987-11-12
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Granted: 1990-07-10
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Expires: 2007-11-12
Abstract
Abstract A semiconductor laser element of the present invention provides a double hetero junction structure having two clad layers and an active layer formed between the two clad layers. High resistance regions are formed vertically to the light propagating direction at almost the same interval as the light wavelength in at least one of the two clad layers. The high resistance regions form a periodic current blocking structure so the semiconductor laser element may oscillate in a single longitudinal mode even in a non-steady state operation.
Inventors
- 👤 Toshihiko Yoshida
- 👤 Haruhisa Takiguchi
- 👤 Shinji Kaneiwa
- 👤 Hiroaki Kudo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 10:03
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/20; H01S5/10; H01S5/12; H01S5/2054; H01S5/2059
Claims Analysis
Total Claims: 42
Claim 1
Independent Claim
149 words
A distributed feedback semiconductor laser device comprising: a substrate; a first clad layer formed on a top surface of said substrate; an active layer formed on said first clad layer; a second clad layer formed on said active layer; a plurality of high resistance regions formed in said second clad layer, each said plurality of high resistance regions being separated by a predetermined lateral distance and extending into said second clad layer a predetermined vertical depth; a third clad layer formed over said second clad layer and said plurality of high resistance regions; a contact layer formed on said third clad layer; a first electrode formed on a bottom surface of said substrate; a second electrode formed on said contact layer; and current injection means for injecting current into the distributed feedback semiconductor laser device so that the distributed feedback semiconductor laser device oscillates in a single longitudinal mode.
Claim 2
Dependent Claim
149 words
A distributed feedback semiconductor laser device comprising: a substrate; a first clad layer formed on a top surface of said substrate; an active layer formed on said first clad layer; a second clad layer formed on said active layer; a plurality of high resistance regions formed in said second clad layer, each said plurality of high resistance regions being separated by a predetermined lateral distance and extending into said second clad layer a predetermined vertical depth; a third clad layer formed over said second clad layer and said plurality of high resistance regions; a contact layer formed on said third clad layer; a first electrode formed on a bottom surface of said substrate; a second electrode formed on said contact layer; and current injection means for injecting current into the distributed feedback semiconductor laser device so that the distributed feedback semiconductor laser device oscillates in a single longitudinal mode.
Claim 3
Dependent Claim
50 words
The distributed feedback semiconductor laser device of claim 1 wherein said substrate and said first clad layer are formed of a p-type material, said active layer is formed of an undoped material, and said second layer, said third clad layer and said contact layer are formed of an n-type material.
Claim 4
Dependent Claim
150 words
A distributed feedback semiconductor laser device comprising: a layered semiconductor structure for use in a semiconductor laser comprising, a substrate; a first clad layer formed on a top surface of said substrate; a plurality of high resistance regions formed in said first clad layer, each said plurality of high resistance regions being separated by a predetermined lateral distance and extending into said first clad layer a predetermined vertical depth; an active layer formed over said first clad layer and said plurality of high resistance regions; a second clad layer formed on said active layer; a contact layer formed on said second clad layer; a first electrode formed on a bottom surface of said substrate; a second electrode formed on said contact layer; and current injection means for injecting current into the distributed feedback semiconductor laser device so that the distributed feedback semiconductor laser device oscillates in a single longitudinal mode.
Claim 5
Dependent Claim
150 words
A distributed feedback semiconductor laser device comprising: a layered semiconductor structure for use in a semiconductor laser comprising, a substrate; a first clad layer formed on a top surface of said substrate; a plurality of high resistance regions formed in said first clad layer, each said plurality of high resistance regions being separated by a predetermined lateral distance and extending into said first clad layer a predetermined vertical depth; an active layer formed over said first clad layer and said plurality of high resistance regions; a second clad layer formed on said active layer; a contact layer formed on said second clad layer; a first electrode formed on a bottom surface of said substrate; a second electrode formed on said contact layer; and current injection means for injecting current into the distributed feedback semiconductor laser device so that the distributed feedback semiconductor laser device oscillates in a single longitudinal mode.
Claim 6
Dependent Claim
46 words
The distributed feedback semiconductor device of claim 3, wherein said substrate and said first clad layer are formed of an n-type material, said active layer is formed of an undoped material and said second clad layer and said contact layer are formed of a p-type material.
Claim 7
Dependent Claim
25 words
The distributed feedback semiconductor device of claim 1, wherein said plurality of high resistance regions are formed by injecting ions into said second clad layer.
Claim 8
Dependent Claim
25 words
The distributed feedback semiconductor device of claim 3, wherein said plurality of high resistance regions are formed by injecting ions into said first clad layer.
Claim 9
Dependent Claim
16 words
The distributed feedback semiconductor device of claim 2, wherein said substrate is formed of p-type InP.
Claim 10
Dependent Claim
18 words
The distributed feedback semiconductor device of claim 2, wherein said first clad layer is formed of p-type InP.
Claim 11
Dependent Claim
17 words
The distributed feedback semiconductor device of claim 2, wherein said active layer is formed of undoped InGaAsP.
Claim 12
Dependent Claim
18 words
The distributed feedback semiconductor device of claim 2, wherein said second clad layer is formed of n-type InP.
Claim 13
Dependent Claim
18 words
The distributed feedback semiconductor device of claim 2, wherein said third clad layer is formed of n-type InP.
Claim 14
Dependent Claim
17 words
The distributed feedback semiconductor device of claim 2, wherein said contact layer is formed of n-type InGaAsP.
Claim 15
Dependent Claim
21 words
The distributed feedback semiconductor device of claim 5, wherein said plurality of high resistance regions are formed by injecting Fe ions.
Claim 16
Dependent Claim
21 words
The distributed feedback semiconductor device of claim 6, wherein said plurality of high resistance regions are formed by injecting Fe ions.
Claim 17
Dependent Claim
16 words
The distributed feedback semiconductor device of claim 1, wherein said first electrode is formed of Au/Zn.
Claim 18
Dependent Claim
16 words
The distributed feedback semiconductor device of claim 1, wherein said second electrode is formed of Au/Ge/Ni.
Claim 19
Dependent Claim
16 words
The distributed feedback semiconductor device of claims 4, wherein said substrate is formed of n-type InP.
Claim 20
Dependent Claim
18 words
The distributed feedback semiconductor device of claim 4, wherein said first clad layer is formed of n-type InP.
Claim 21
Dependent Claim
17 words
The distributed feedback semiconductor device of claim 4, wherein said active layer is formed of undoped InGaAsP.
Claim 22
Dependent Claim
18 words
The distributed feedback semiconductor device of claim 4, wherein said second clad layer is formed of p-type InP.
Claim 23
Dependent Claim
17 words
The distributed feedback semiconductor device of claim 4, wherein said contact layer is formed of p-type InGaAsP.
Claim 24
Dependent Claim
100 words
A layered semiconductor structure for use in a distributed feedback semiconductor laser comprising: a substrate; a first clad layer formed on a top surface of said substrate; an active layer formed on said first clad layer; a second clad layer formed on said active layer; a plurality of high resistance regions formed in said second clad layer, each said plurality of high resistance regions being separated by a predetermined lateral distance and extending into said second clad layer a predetermined vertical depth; and a third clad layer formed over said second clad layer and said plurality of high resistance regions.
Claim 25
Dependent Claim
100 words
A layered semiconductor structure for use in a distributed feedback semiconductor laser comprising: a substrate; a first clad layer formed on a top surface of said substrate; an active layer formed on said first clad layer; a second clad layer formed on said active layer; a plurality of high resistance regions formed in said second clad layer, each said plurality of high resistance regions being separated by a predetermined lateral distance and extending into said second clad layer a predetermined vertical depth; and a third clad layer formed over said second clad layer and said plurality of high resistance regions.
Claim 26
Dependent Claim
43 words
The layered semiconductor device of claim 22, wherein said substrate and said first clad layer are formed of a p-type material, said active layer is formed of an undoped material and said second and third clad layers are formed of an n-type material.
Claim 27
Dependent Claim
15 words
The layered semiconductor structure of claim 23, wherein said substrate is formed of p-type InP.
Claim 28
Dependent Claim
17 words
The layered semiconductor structure of claim 23, wherein said first clad layer is formed of p-type InP.
Claim 29
Dependent Claim
16 words
The layered semiconductor structure of claim 23, wherein said active layer is formed of undoped InGaAsP.
Claim 30
Dependent Claim
17 words
The layered semiconductor structure of claim 23, wherein said second clad layer is formed of n-type InP.
Claim 31
Dependent Claim
17 words
The layered semiconductor structure of claim 23, wherein said third clad layer is formed of n-type InP.
Claim 32
Dependent Claim
24 words
The layered semiconductor structure of claim 22, wherein said plurality of high resistance regions are formed by injecting ions into said second clad layer.
Claim 33
Dependent Claim
20 words
The layered semiconductor structure of claim 29, wherein said plurality of high resistance regions are formed by injecting Fe ions.
Claim 34
Dependent Claim
90 words
A layered semiconductor structure for use in a distributed feedback semiconductor laser comprising: a substrate; a first clad layer formed on a top surface of said substrate; a plurality of high resistance regions formed in said first clad layer, each said plurality of high resistance regions being separated by a predetermined lateral distance and extending into said first clad layer a predetermined vertical depth; an active layer formed over said first clad layer and said plurality of high resistance regions; and a second clad layer formed on said active layer.
Claim 35
Dependent Claim
90 words
A layered semiconductor structure for use in a distributed feedback semiconductor laser comprising: a substrate; a first clad layer formed on a top surface of said substrate; a plurality of high resistance regions formed in said first clad layer, each said plurality of high resistance regions being separated by a predetermined lateral distance and extending into said first clad layer a predetermined vertical depth; an active layer formed over said first clad layer and said plurality of high resistance regions; and a second clad layer formed on said active layer.
Claim 36
Dependent Claim
41 words
The layered semiconductor structure of claim 31, wherein said substrate and said first clad layer are formed of an n-type material, said active layer is formed of an undoped material and said second clad layer is formed of a p-type material.
Claim 37
Dependent Claim
15 words
The layered semiconductor structure of claim 32, wherein said substrate is formed of n-type InP.
Claim 38
Dependent Claim
17 words
The layered semiconductor structure of claim 32, wherein said first clad layer is formed of n-type InP.
Claim 39
Dependent Claim
16 words
The layered semiconductor structure of claim 32, wherein said active layer is formed of undoped InGaAsP.
Claim 40
Dependent Claim
17 words
The layered semiconductor structure of claim 32, wherein said second clad layer is formed of p-type InP.
Claim 41
Dependent Claim
24 words
The layered semiconductor structure of claim 31, wherein said plurality of high resistance regions are formed by injected ions into said first clad layer.
Claim 42
Dependent Claim
20 words
The layered semiconductor structure of claim 37, wherein said plurality of high resistance regions are formed by injecting Fe ions.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-07-09 | 1994-01-08 | 1994-07-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-09 | 1998-01-08 | 1998-07-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-09 | 2002-01-08 | 2002-07-10 | $7700.00 | Window Closed / Lapsed |