US5257276A
Expired / Lapsed
US
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Strained layer InP/InGaAs quantum well laser
Assignee: California Institute of Technology
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Filing: 1992-04-03
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Granted: 1993-10-26
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Expires: 2012-04-03
Abstract
Abstract Strained layer single or multiple quantum well lasers include an InP substrate, a pair of lattice-matched InGaAsP quarternary layers epitaxially grown on the substrate surrounding a pair of lattice matched In 0 .53 Ga 0 .47 As ternary layers surrounding one or more strained active layers of epitaxially grown, lattice-mismatched In 0 .75 Ga 0 .25 As. The level of strain is selected to control the bandgap energy to produce laser output having a wavelength in the range of 1.6 to 2.5 μm. The multiple quantum well structure uses between each active layer. Diethyl zinc is used for p-type dopant in an InP cladding layer at a concentration level in the range of about 5×10 17 /cm 3 to about 2×10 18 /cm 3 . Hydrogen sulfide is used for n-type dopant in the substrate ORIGIN OF THE INVENTION The invention described herein was made in the performance of work under a NASA contract, and is subject to the provisions of Public Law 96-517 (35 USC 202) in which the Contractor has elected to retain title
Inventors
- 👤 Siamak Forouhar
- 👤 Anders G. Larsson
- 👤 Alexander Ksendzov
- 👤 Robert J. Lang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:59
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/30; H01S5/34; H01S5/343; H01S5/34313; B; B82; B82Y; B82Y20/00; H01S5/20; H01S5/22; H01S5/305; H01S5/34306
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
85 words
A strained layer quantum well laser, comprising: an InP substrate; a pair of lattice-matched InGaAsP quarternary layers epitaxially grown on the substrate; one or more strained active layers of epitaxially grown, lattice-mismatched InGaAs within the quarternary layers; and means for injecting current into the one or more active layers to produce laser output, the level of strain in the one or more active layers controlling the bandgap energy to produce laser output having a wavelength in the range of about 1.6 to about 2.5 μm.
Claim 2
Dependent Claim
85 words
A strained layer quantum well laser, comprising: an InP substrate; a pair of lattice-matched InGaAsP quarternary layers epitaxially grown on the substrate; one or more strained active layers of epitaxially grown, lattice-mismatched InGaAs within the quarternary layers; and means for injecting current into the one or more active layers to produce laser output, the level of strain in the one or more active layers controlling the bandgap energy to produce laser output having a wavelength in the range of about 1.6 to about 2.5 μm.
Claim 3
Dependent Claim
36 words
The strained layer quantum well laser claimed in claim 1 further comprising: a pair of lattice-matched InGaAs ternary layers epitaxially grown on the substrate between the quarternary layers and surrounding the one or more active layers.
Claim 4
Dependent Claim
36 words
The strained layer quantum well laser claimed in claim 2 wherein each of the one or more active layers comprises: In x Ga 1-x As wherein x is in the range of about 0.7 to 1.
Claim 5
Dependent Claim
15 words
The strained layer quantum well laser claimed in claim 3 wherein x is about 0.73.
Claim 6
Dependent Claim
39 words
The strained layer quantum well laser claimed in claim 3 further comprising: a plurality of said active layers forming a multiple quantum well laser structure; and a lattice-matched InGaAs barrier layer epitaxially grown between each pair of active layers.
Claim 7
Dependent Claim
29 words
The strained layer quantum well laser claimed in claim 5 wherein each barrier layer comprises: In x Ga 1-x As wherein x is in the range of about 0.53.
Claim 8
Dependent Claim
35 words
The strained layer quantum well laser claimed in claim 5 wherein each barrier layer comprises: In 1-x Ga x As y P 1-y where x is in the range of about 0 to about 0.47.
Claim 9
Dependent Claim
29 words
The strained layer quantum well laser claimed in claim 3 further comprising: two to five active layers each in the range of about 1 to about 12 nm thick.
Claim 10
Dependent Claim
19 words
The strained layer quantum well laser claimed in claim 8 wherein the active layers are about 3.5 nm thick.
Claim 11
Dependent Claim
26 words
The strained layer quantum well laser claimed in claim 9 wherein the barrier layers are in the range of about 5 to about 40 nm thick.
Claim 12
Dependent Claim
19 words
The strained layer quantum well laser claimed in claim 10 wherein the barrier layers are about 6.5 nm thick.
Claim 13
Dependent Claim
15 words
The strained layer quantum well laser claimed in claim 8 further comprising: four active layers.
Claim 14
Dependent Claim
41 words
The strained layer quantum well laser claimed in claim 8 further comprising: four of said active layers each on the order of about 3.5 nm thick; and three of said barrier layers each on the order of about 6.5 nm thick.
Claim 15
Dependent Claim
33 words
The strained layer quantum well laser claimed in claim 8 wherein an energy level differential exists between each active and barrier layer of on the order of about 0.05 to about 0.3 eV.
Claim 16
Dependent Claim
29 words
The strained layer quantum well laser claimed in claim 8 wherein an energy level differential exists between each active and barrier layer of on the order of about 0.05.
Claim 17
Dependent Claim
26 words
The strained layer quantum well laser claimed in claim 3 further comprising: an InP cladding layer epitaxially grown on the quarternary layer furthest from the substrate.
Claim 18
Dependent Claim
31 words
The strained layer quantum well laser claimed in claim 16 wherein said cladding layer is formed into a ridge waveguide for directing injected current into the one or more active layers.
Claim 19
Dependent Claim
34 words
The strained layer quantum well laser claimed in claim 17 further comprising: p-type dopant in the cladding layer at a concentration level in the range of about 5×10 17 to about 2×10 18 .
Claim 20
Dependent Claim
17 words
The strained layer quantum well laser claimed in claim 18 wherein said p-type dopant is diethyl zinc.
Claim 21
Dependent Claim
31 words
The strained layer quantum well laser claimed in claim 3 further comprising: n-type dopant in the substrate at a concentration level in the range of about 1×10 18 /cm 3 .
Claim 22
Dependent Claim
17 words
The strained layer quantum well laser claimed in claim 20 wherein said n-type dopant is hydrogen sulfide.
Claim 23
Dependent Claim
36 words
The strained layer quantum well laser claimed in claim 3 wherein said active layer is a single active layer in the range of about 1 to about 12 nm thick forming a single quantum well structure.
Claim 24
Dependent Claim
33 words
The strained layer quantum well laser claimed in claim 3 wherein said active layer is a single active layer in the range of about 12 nm thick forming a single quantum well structure.
Claim 25
Dependent Claim
30 words
The strained layer quantum well laser claimed in claim 23 wherein an energy level differential exists between said active layer and said ternary layers on the order of 0.15 eV.
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) | 1996-10-25 | 1997-04-26 | 1997-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-10-25 | 2001-04-26 | 2001-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-10-25 | 2005-04-26 | 2005-10-26 | $7700.00 | Window Closed / Lapsed |