US5255281A
Expired / Lapsed
US
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Semiconductor laser having double heterostructure
Assignee: Fujitsu Ltd
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Filing: 1992-12-24
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Granted: 1993-10-19
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Expires: 2012-12-24
Abstract
Abstract A semiconductor laser includes a substrate having a (100) face as its main surface, where the substrate has a stripe of a first mesa extending in a <110> direction of the substrate and including a (111)B face as its sloping surface, a buried layer formed on the substrate excluding a top surface of the stripe of the first mesa so that the (111)B face of the stripe of the first mesa is covered a sloping surface part of the buried layer, where the top surface of the stripe of the first mesa is the (100) face of the substrate and forms a stripe of a second mesa together with the sloping surface of the buried layer and the stripe of the second mesa has a smaller inclination than the stripe of the first mesa, and a double heterostructure made up of a plurality of semiconductor layers and formed on the stripe of the second mesa. The double heterostructure has a substantially trapezoidal cross section which is determined by the stripe of the second mesa.
Inventors
- 👤 Mami Sugano
- 👤 Akira Furuya
- 👤 Toshiyuki Tanahashi
- 👤 Makoto Kondo
- 👤 Chikashi Anayama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:51
CPC Classifications
B; B82; B82Y; B82Y20/00; H; H01; H01S; H01S5/00; H01S5/10; H01S5/16; H01S5/20; H01S5/22; H01S5/223; H01S5/2232; H01S5/30; H01S5/32; H01S5/323; H01S5/32308; H01S5/32325; H01S5/34; H01S5/343; H01S5/34326; H10; H10H; H10H20/00; H10H20/01; H10H20/011; H10H20/013; H01S5/1053; H01S5/1064; H01S5/2201; H01S5/2205; H01S5/2206; H01S5/2209; H01S5/221; H01S5/2234; H01S5/2235; H01S5/227; H01S5/2272; H01S5/3211; H01S5/3235; H01S5/32391
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
171 words
A semiconductor laser comprising: a substrate having a (100) face as its main surface, said substrate having a stripe of a first mesa extending in a <110> direction of the substrate and including a (111)B face as its sloping surface; a buried layer formed on said substrate excluding a top surface of the stripe of the first mesa so that the (111)B face of the stripe of the first mesa is covered a sloping surface part of said buried layer, said top surface of the stripe of the first mesa being the (100) face of said substrate and forming a stripe of a second mesa together with the sloping surface of said buried layer, said stripe of the second mesa having a smaller inclination than said stripe of the first mesa; and a double heterostructure made up of a plurality of semiconductor layers and formed on the stripe of the second mesa, said double heterostructure having a substantially trapezoidal cross section which is determined by said stripe of the second mesa.
Claim 2
Dependent Claim
171 words
A semiconductor laser comprising: a substrate having a (100) face as its main surface, said substrate having a stripe of a first mesa extending in a <110> direction of the substrate and including a (111)B face as its sloping surface; a buried layer formed on said substrate excluding a top surface of the stripe of the first mesa so that the (111)B face of the stripe of the first mesa is covered a sloping surface part of said buried layer, said top surface of the stripe of the first mesa being the (100) face of said substrate and forming a stripe of a second mesa together with the sloping surface of said buried layer, said stripe of the second mesa having a smaller inclination than said stripe of the first mesa; and a double heterostructure made up of a plurality of semiconductor layers and formed on the stripe of the second mesa, said double heterostructure having a substantially trapezoidal cross section which is determined by said stripe of the second mesa.
Claim 3
Dependent Claim
17 words
The semiconductor laser as claimed in claim 1, wherein said buried layer forms a current confinement part.
Claim 4
Dependent Claim
51 words
The semiconductor laser as claimed in claim 1, wherein said buried layer is made of a material selected from a group consisting of a semiconductor of a conductor type opposite to that of a semiconductor forming said substrate and a semiconductor having a high resistance compared to that of said substrate.
Claim 5
Dependent Claim
17 words
The semiconductor laser as claimed in claim 1, wherein said substrate is made of a p-type semiconductor.
Claim 6
Dependent Claim
93 words
The semiconductor laser as claimed in claim 1, wherein said substrate is made of GaAs, and said double heterostructure includes a first cladding layer, an active layer formed on the first cladding layer and a second cladding layer formed on the active layer, said active layer being made of one of InGaP and AlGaInP, said first and second cladding layers being both made of one of AlGaInP and AlInP but of mutually opposite conductor types, said first and second cladding layers having an energy band gap greater than that of said active layer.
Claim 7
Dependent Claim
79 words
The semiconductor laser as claimed in claim 5, wherein said substrate is made of p-type GaAs, and said semiconductor laser further comprises a first p-type buffer layer interposed between said p-type GaAs substrate and said first cladding layer, said first p-type buffer layer being made of a material selected from a group consisting of InGaP, AlGaInP and AlGaAs and having an intermediate energy band gap which falls between energy band gaps of said first cladding layer and said substrate.
Claim 8
Dependent Claim
39 words
The semiconductor laser as claimed in claim 6, which further comprises a second p-type buffer layer which is interposed between said p-type GaAs substrate and said first p-type buffer layer, said second p-type buffer layer being made of GaAs.
Claim 9
Dependent Claim
35 words
The semiconductor laser as claimed in claim 5, wherein said second cladding layer is made of n-type AlGaInP and includes a mole fraction of Al which is smaller than that of said first cladding layer.
Claim 10
Dependent Claim
54 words
The semiconductor laser as claimed in claim 5, which further comprises a p-type buffer layer which is formed only on the (100) face which is the top surface of the stripe of the first mesa, said p-type buffer layer being made of a material selected from a group consisting of InGaP, AlGaInP and AlGaAs.
Claim 11
Dependent Claim
26 words
The semiconductor laser as claimed in claim 1, wherein said buried layer is made of a material selected from a group consisting of GaAs and AlGaAs.
Claim 12
Dependent Claim
42 words
The semiconductor laser as claimed in claim 1, wherein said buried layer includes a layer which is made of a material having a energy band gap which is sufficiently wide such that a potential wall for blocking injection minority carriers is generated.
Claim 13
Dependent Claim
57 words
The semiconductor laser as claimed in claim 1, wherein said substrate is made of p-type InP, and said double heterostructure includes a first cladding layer, an active layer formed on the first cladding layer and a second cladding layer formed on the active layer, said first and second cladding layers being made of mutually opposite conductor types.
Claim 14
Dependent Claim
35 words
The semiconductor laser as claimed in claim 12, wherein said active layer is made of InGaAsP, said first cladding layer is made of p-type InP, and said second cladding layer is made of n-type InP.
Claim 15
Dependent Claim
28 words
The semiconductor laser as claimed in claim 13, wherein said buried layer is made of a material selected from a group consisting of n-type InGaAs and n-type AlInAs.
Claim 16
Dependent Claim
35 words
The semiconductor laser as claimed in claim 12, wherein said active layer is made of InGaAs, said first cladding layer is made of p-type AlInAs, and said second cladding layer is made of n-type AlInAs.
Claim 17
Dependent Claim
28 words
The semiconductor laser as claimed in claim 15, wherein said buried layer is made of a material selected from a group consisting of n-type InGaAs and n-type AlInAs.
Claim 18
Dependent Claim
27 words
The semiconductor laser as claimed in claim 15, which further comprises a p-type InP buffer layer interposed between said p-type InP substrate and said first cladding layer.
Claim 19
Dependent Claim
45 words
The semiconductor laser as claimed in claim 1, wherein said stripe of the first mesa includes a tapered part where a width along the <110> direction of the sloping surface which is approximately the (111)B face decreases towards an edge surface of the semiconductor laser.
Claim 20
Dependent Claim
37 words
The semiconductor laser as claimed in claim 18, wherein said stripe of the first mesa includes a prism shaped part which does not have the (100) face and terminates at the edge surface of the semiconductor laser.
Claim 21
Dependent Claim
37 words
The semiconductor laser as claimed in claim 19, wherein said prism shaped part has a height which is lower than a height of the (100) face at the type surface of the stripe of the first mesa.
Claim 22
Dependent Claim
24 words
The semiconductor laser as claimed in claim 1, wherein said buried layer completely covers the (111)B face of the stripe of the first mesa.
References Cited (Backward Citations)
JPS55158689A
Cited
US4506366A
Cited
JPS5864085A
Cited
EP0136097A2
Cited
US4701927A
Cited
US4692927A
Cited
US4894840A
Cited
US4757509A
Cited
EP0234955A2
Cited
JPS62200784A
Cited
US4813050A
Cited
US4932033A
Cited
JPS6381884A
Cited
US4974232A
Cited
JPS6430287A
Cited
JPS6432692A
Cited
JPH01313982A
Cited
US4984244A
Cited
US4940672A
Cited
US4994143A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-10-18 | 1997-04-19 | 1997-10-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-10-18 | 2001-04-19 | 2001-10-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-10-18 | 2005-04-19 | 2005-10-19 | $7700.00 | Window Closed / Lapsed |