Patent US4546480A successfully refreshed from Google Patents.
US4546480A
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US
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Injection lasers with quantum size effect transparent waveguiding
Assignee: Xerox Corp
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Filing: 1983-08-19
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Granted: 1985-10-08
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Expires: 2003-08-19
Abstract
Abstract An injection laser is provided with quantum size effect transparent waveguiding. The laser includes an active layer having an active region wherein carrier recombination occurs under lasing conditions. The active layer has passive waveguide end regions between the active region and the laser end facets that are sufficiently thin in layer thickness to form a transparent waveguide having a quantum well effect so that radiative recombination will not occur in these regions.
Inventors
- 👤 Robert D. Burnham
- 👤 Donald R. Scifres
- 👤 William Streifer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:12
CPC Classifications
H; H10; H10H; H10H29/00; H10H29/10; H01; H01S; H01S5/00; H01S5/10; H01S5/16; H01S5/1053; H01S5/106; H01S5/30; H01S5/34; H01S5/3428
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
157 words
In an injection laser comprising a plurality of contiguous semiconductor layers deposited on a substrate, one of said layers being an active layer and having a lower bandgap and higher index of refraction relative to at least cladding layers immediately adjacent to said active layer, said active layer having an active region to permit radiative recombination and support radiation propagating under lasing conditions in a cavity established between transverse end facets of the laser, means incorporated into said laser to confine current to said active region, the extremities of said active region falling short of said end facets so that the regions of said active layer between said active region and said end facets function as a passive waveguide for the propagating radiation, said passive waveguide regions of said active layer being sufficiently thin in layer thickness to form a transparent waveguide having a quantum well effect so that radiative recombination will not occur in these regions.
Claim 2
Dependent Claim
157 words
In an injection laser comprising a plurality of contiguous semiconductor layers deposited on a substrate, one of said layers being an active layer and having a lower bandgap and higher index of refraction relative to at least cladding layers immediately adjacent to said active layer, said active layer having an active region to permit radiative recombination and support radiation propagating under lasing conditions in a cavity established between transverse end facets of the laser, means incorporated into said laser to confine current to said active region, the extremities of said active region falling short of said end facets so that the regions of said active layer between said active region and said end facets function as a passive waveguide for the propagating radiation, said passive waveguide regions of said active layer being sufficiently thin in layer thickness to form a transparent waveguide having a quantum well effect so that radiative recombination will not occur in these regions.
Claim 3
Dependent Claim
20 words
In the injection laser of claim 1 wherein said active layer is a single quantum well structure of uniform thickness.
Claim 4
Dependent Claim
23 words
In the injection laser of claim 2 wherein said active layer has a thickness in the range of about 100A to 500 Å.
Claim 5
Dependent Claim
17 words
In the injection laser of claim 1 wherein said active layer comprises a multiple quantum well structure.
Claim 6
Dependent Claim
20 words
In the injection laser of claim 1 wherein said active region is of thicker cross-section than said passive waveguide regions.
Claim 7
Dependent Claim
46 words
In the injection laser of claim 5 wherein said active region has a thickness in the range of about 500 Å to 10,000 Å and said passive waveguide regions of said active layer have a thickness in the range of about 5 Å to 500 Å.
Claim 8
Dependent Claim
30 words
In the injection laser of claim 6 wherein said passive waveguide regions of said active layer have a preferred thickness in the range of about 50 Å to 200 Å.
Claim 9
Dependent Claim
18 words
In the injection laser of claim 1 wherein said passive waveguide regions are multiple quantum well waveguide regions.
Claim 10
Dependent Claim
40 words
In the injection laser of claim 8 wherein said quantum well passive waveguide regions comprise alternating layers of undoped GaAs/Ga 1-y Al y As, each of said layers being in the range of about 40 Å to 50 Å thick.
Claim 11
Dependent Claim
19 words
In the injection laser of claim 8 wherein said active region also comprise a multiple quantum well active region.
Claim 12
Dependent Claim
59 words
In the injection laser of claim 10 wherein said multiple quantum well passive waveguide regions and said multiple quantum well active region comprise alternating layers of undoped GaAs/Ga 1-y Al y As, the thickness of the well layers comprising a portion of said active region being larger than the thickness of the well layers of said passive waveguide regions.
References Cited (Backward Citations)
US4297652A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-10-07 | 1989-04-08 | 1989-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-10-07 | 1993-04-08 | 1993-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-10-07 | 1997-04-08 | 1997-10-08 | $7700.00 | Window Closed / Lapsed |