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Patent US4416012A successfully refreshed from Google Patents.
US4416012A
Expired / Lapsed
US
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W-Guide buried heterostructure laser
Assignee: RCA Corp
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Filing: 1981-11-19
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Granted: 1983-11-15
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Expires: 2001-11-19
Abstract
Abstract The invention is an improved buried heterostructure laser wherein the improvement comprises a cladding layer which is interposed between the mesa and the burying region and has a refractive index less than that of the burying region and the effective refractive index of the fundamental transverse mode. The discrimination against higher order modes of propagation provided by the structure permits the use of a wider active layer and thus a larger emitting area.
Inventors
- 👤 Dan Botez
- 👤 Michael Ettenberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:17
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/20; H01S5/22; H01S5/227; H01S5/205; H01S5/2275
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
170 words
In a buried heterostructure laser which emits light at a particular wavelength comprising a substrate having two opposed major surfaces, a mesa having side walls and overlying a portion of said first major surface, a cladding layer overlying the side walls of said mesa and the remainder of said first surface of said substrate, and a burying region overlying said cladding layer wherein said mesa comprises a first confinement layer overlying a portion of said surface of said substrate, an active layer overlying said first confinement layer and a second confinement layer overlying said active layer and wherein electrical contacts overlie said second confinement layer and a portion of said second major surface of said substrate; the improvement comprising said cladding layer having a refractive index at said wavelength which is less than the effective refractive index of the fundamental transverse mode in said mesa and wherein the refractive index of said burying region is greater than or equal to the effective refractive index of said mode in said mesa.
Claim 2
Dependent Claim
170 words
In a buried heterostructure laser which emits light at a particular wavelength comprising a substrate having two opposed major surfaces, a mesa having side walls and overlying a portion of said first major surface, a cladding layer overlying the side walls of said mesa and the remainder of said first surface of said substrate, and a burying region overlying said cladding layer wherein said mesa comprises a first confinement layer overlying a portion of said surface of said substrate, an active layer overlying said first confinement layer and a second confinement layer overlying said active layer and wherein electrical contacts overlie said second confinement layer and a portion of said second major surface of said substrate; the improvement comprising said cladding layer having a refractive index at said wavelength which is less than the effective refractive index of the fundamental transverse mode in said mesa and wherein the refractive index of said burying region is greater than or equal to the effective refractive index of said mode in said mesa.
Claim 3
Dependent Claim
29 words
The article of claim 1 wherein the ratio of the lateral width of said cladding layer to the lateral width of said active layer is less than about 1.
Claim 4
Dependent Claim
20 words
The article of claim 2 wherein the width of said active region is between about 2 and about 5 micrometers.
Claim 5
Dependent Claim
19 words
The article of claim 2 wherein the width of said cladding layer is between about 0.1 and 2 micrometers.
Claim 6
Dependent Claim
15 words
The article according to claim 2 wherein said ratio is between about 0.1 and 0.5.
Claim 7
Dependent Claim
29 words
The article according to claim 1 wherein the difference in the refractive indices of said burying region and said cladding layer at said wavelength is less than about 0.5.
Claim 8
Dependent Claim
34 words
The article according to claim 1 wherein a buffer layer is interposed between said substrate and said mesa and a capping layer is interposed between a second confinement layer and a first electrical contact.
Claim 9
Dependent Claim
51 words
The article according to claim 7 wherein a guide layer is interposed between said active layer and one of said confinement layers and wherein said guide layer has a refractive index at said wavelength which is greater than that of said confinement layer and less than that of said active layer.
Claim 10
Dependent Claim
34 words
The article according to claim 7 wherein said substrate, buffer layer and capping layer are composed of GaAs and said confinement layers, said cladding layer and said burying region are composed of AlGaAs alloys.
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) | 1986-11-14 | 1987-05-16 | 1987-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-11-14 | 1991-05-16 | 1991-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-11-14 | 1995-05-16 | 1995-11-15 | $7700.00 | Window Closed / Lapsed |