Patent US4249142A successfully refreshed from Google Patents.
US4249142A
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Enhancement of lowest order mode operation in nonplanar DH injection lasers
Assignee: Xerox Corp
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Filing: 1978-11-30
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Granted: 1981-02-03
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Expires: 1998-11-30
Abstract
Abstract By employing a channel in the substrate of a GaAs-GaAlAs injection laser, the active waveguiding layer of the laser can be made to have constricted regions above the shoulders of the substrate channel. The constricted regions are characterized as being of thin cross section as compared to immediate adjacent areas of the active layer and may be provided at one terminus point of the region with a pinch-off in the active layer. This configuration, upon proper stripe placement and current confinement through this region into the substrate channel will enhance light wave propagation in this region and improve fundamental transverse mode operation.
Inventors
- 👤 Robert D. Burnham
- 👤 Donald R. Scifres
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:54
CPC Classifications
B; B65; B65D; B65D53/00
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
174 words
In an injection laser comprising a substrate body having a surface with an elongated channel in said surface and having shoulders at the upper extremities thereof adjacent said surface, first, second and third layers of semiconductor material sequentially formed on said substrate and in said channel, said second layer having a material with a higher index of refraction and lower bandgap than the material of said first and third layers and forming the active layer for said laser, and constricted region formed in said active layer above at least one of said shoulders, current confinement means located above said constricted region and offset relative to said elongated channel to confine the pumping current through said constricted region whereby light wave propagation under lasing conditions occurs in said constricted region, and means located below said constricted region adjacent said channel and in the surface of said substrate for restricting the flow of pumping current to a path through said channel, both of said means contributing to the inducement light wave propagation in said constricted region.
Claim 2
Dependent Claim
174 words
In an injection laser comprising a substrate body having a surface with an elongated channel in said surface and having shoulders at the upper extremities thereof adjacent said surface, first, second and third layers of semiconductor material sequentially formed on said substrate and in said channel, said second layer having a material with a higher index of refraction and lower bandgap than the material of said first and third layers and forming the active layer for said laser, and constricted region formed in said active layer above at least one of said shoulders, current confinement means located above said constricted region and offset relative to said elongated channel to confine the pumping current through said constricted region whereby light wave propagation under lasing conditions occurs in said constricted region, and means located below said constricted region adjacent said channel and in the surface of said substrate for restricting the flow of pumping current to a path through said channel, both of said means contributing to the inducement light wave propagation in said constricted region.
Claim 3
Dependent Claim
23 words
The injection laser of claim 1 wherein said constricted region is characterized as having the thinnest cross sectional contour of said second layer.
Claim 4
Dependent Claim
97 words
The injection laser of claim 1 wherein there is a constricted region formed in said second layer above both of said shoulders, current confinement means located above both of said constricted regions relative to the upper surface of the laser to confine the pumping current through said constricted regions, and means located below both of said constricted regions adjacent said channel and in the surface of said substrate for restricting the flow of pumping current to a path through said channel, both of said means contributing to the inducement of light wave propagation in said constricted region.
Claim 5
Dependent Claim
23 words
The injection laser of claim 1 wherein there is a pinch-off in said second layer defining one terminal point of said constricted region.
References Cited (Backward Citations)
US4099999A
Cited
US4166253A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-02-03 | 1984-08-04 | 1985-02-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-02-03 | 1988-08-04 | 1989-02-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-02-03 | 1992-08-04 | 1993-02-03 | $7700.00 | Window Closed / Lapsed |