US4335461A
Expired / Lapsed
US
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Injection lasers with lateral spatial thickness variations (LSTV) in the active layer
Assignee: Xerox Corp
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Filing: 1980-08-25
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Granted: 1982-06-15
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Expires: 2000-08-25
Abstract
Abstract Enhanced higher order mode discrimination is obtained in injection lasers with lateral spatial thickness variations (LSTV) in the active layer with (1) the proper refractive index quantitative differences in the cladding layers contiguous with the active layer and (2) by fabricating the active layer to have a rapidity in its LSTV from the maximum thickness to the minimum thickness that is very gradual.
Inventors
- 👤 William Streifer
- 👤 Donald R. Scifres
- 👤 Robert D. Burnham
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 10:33
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/10; H01S5/1053; H01S5/106; H01S5/20; H01S5/22; H01S5/227; H01S5/2275
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
152 words
In an injection laser comprising a plurality of contiguous layers of semiconductor material, one of said layers fabricated to form an active layer for optical wave propagation under lasing conditions, a cladding layer contiguous with each surface of said active layer and each having a higher bandgap and a lower refractive index than said active layer, said active layer having an active region with a lateral spatial variation in thickness extending from a central point of maximum thickness to adjacent points of minimum thickness, the improvement comprising. means in said cladding layers to produce a quantitative difference in their relative refractive indices and the lateral spatial variation of the thickness of said region governed by the ratio of the difference between said maximum and minimum thicknesses relative to said maximum thicknesses in conjunction with the rapidity from said maximum thickness to said minimum thickness being in the range of 0.01 to 0.05.
Claim 2
Dependent Claim
152 words
In an injection laser comprising a plurality of contiguous layers of semiconductor material, one of said layers fabricated to form an active layer for optical wave propagation under lasing conditions, a cladding layer contiguous with each surface of said active layer and each having a higher bandgap and a lower refractive index than said active layer, said active layer having an active region with a lateral spatial variation in thickness extending from a central point of maximum thickness to adjacent points of minimum thickness, the improvement comprising. means in said cladding layers to produce a quantitative difference in their relative refractive indices and the lateral spatial variation of the thickness of said region governed by the ratio of the difference between said maximum and minimum thicknesses relative to said maximum thicknesses in conjunction with the rapidity from said maximum thickness to said minimum thickness being in the range of 0.01 to 0.05.
Claim 3
Dependent Claim
22 words
In the injection laser of claim 1 wherein said means comprises a compositional difference in the semiconductor material comprising said cladding layers.
Claim 4
Dependent Claim
24 words
In the injection laser of claim 2 wherein said compositional difference is the percentage of aluminum in the semiconductor material of gallium aluminum arsenide.
Claim 5
Dependent Claim
19 words
In the injection laser of claim 3 wherein said compositional difference is in the range of 10% to 60%.
Claim 6
Dependent Claim
34 words
In the injection laser of claim 1 which includes narrow current confinement means to confine a substantial portion of the current supplied to said laser to the vicinity of said active region central point.
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) | 1985-06-14 | 1985-12-14 | 1986-06-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-06-14 | 1989-12-14 | 1990-06-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-06-14 | 1993-12-14 | 1994-06-15 | $7700.00 | Window Closed / Lapsed |