US3978426A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heterostructure devices including tapered optical couplers
Assignee: AT&T Inc
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Filing: 1975-03-11
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Granted: 1976-08-31
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Expires: 1995-03-11
Abstract
Abstract Described is a double heterostructure junction laser in which the active region tapers to zero thickness within the structure, causing light to couple into an adjacent, underlying passive waveguide layer. Also described is a laser device in which the passive waveguide layer terminates in a region of increased thickness adjacent a laser output face. In addition, LPE and MBE techniques for fabricating the tapers are described.
Inventors
- 👤 Ralph Andre Logan
- 👤 James Logan Merz
- 👤 Franz Karl Reinhart
- 👤 Harry Gregory White
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 13:54
CPC Classifications
H; H10; H10H; H10H20/00; H10H20/80; H10H20/81; H10H20/811; H01; H01S; H01S5/00; H01S5/02; H01S5/026; H01S5/0265; H01S5/10; H01S5/1028; H01S5/1032; H01S5/16; H01S5/164; H10H20/822; H10H20/824; H10P; H10P14/00; H10P14/20; H10P14/26; H10P14/263; H10P14/265; H10P14/27; H10P14/271; H10P14/272; H10P14/29; H10P14/2901; H10P14/2907; H10P14/2911; H10P14/34; H10P14/3402; H10P14/3414; H10P14/3421; Y; Y10; Y10S; Y10S117/00; Y10S117/918
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
112 words
A double heterostructure optical device comprising: first and second wide bandgap layers, a narrower bandgap region intermediate to and contiguous with said first and second layers, and adapted for the propagation of radiation therein, characterized in that said region includes a passive optical waveguide layer having a bandgap less than that of said first and second layers and an active layer contiguous with said waveguide layer, said active layer having a bandgap less than that of said waveguide layer and terminating at one end within said device in a smooth taper effective to couple radiation from said active layer into said waveguide layer, said taper extending in the direction of radiation propagation.
Claim 2
Dependent Claim
112 words
A double heterostructure optical device comprising: first and second wide bandgap layers, a narrower bandgap region intermediate to and contiguous with said first and second layers, and adapted for the propagation of radiation therein, characterized in that said region includes a passive optical waveguide layer having a bandgap less than that of said first and second layers and an active layer contiguous with said waveguide layer, said active layer having a bandgap less than that of said waveguide layer and terminating at one end within said device in a smooth taper effective to couple radiation from said active layer into said waveguide layer, said taper extending in the direction of radiation propagation.
Claim 3
Dependent Claim
50 words
The device of claim 1 including an output face from which radiation emanates, said waveguide layer including a zone adjacent said face which is of greater thickness than the remainder of said waveguide layer, the thickness of said zone decreasing gradually from said face toward the interior of said device.
Claim 4
Dependent Claim
39 words
The device of claim 1 wherein the other end of said active layer terminates in a second taper within said device, both of said tapers extending in the direction of radiation propagation but in directions opposite to one another.
Claim 5
Dependent Claim
71 words
The device of claim 1 wherein said first and second layers comprise Al x Ga 1 -x R and Al y Ga 1 -y R, where R includes at least As, and x > 0, y > 0, said waveguide layer comprises Al z Ga 1 -z R, 0 < z < x and y, and said active layer comprises Al r Ga 1 -r As, 0 ≦ r < z.
Claim 6
Dependent Claim
15 words
The device of claim 4 wherein r = 0 and said active layer comprises GaAs.
Claim 7
Dependent Claim
13 words
The device of claim 4 wherein R includes P as well as As.
Claim 8
Dependent Claim
26 words
The device of claim 1 wherein said first and second layers have opposite conductivity types and said waveguide and active layers have the same conductivity type.
Claim 9
Dependent Claim
34 words
The device of claim 7 includes means for forward biasing said device and supplying current in excess of the lasing threshold of said active layer, thereby to generate laser radiation in said active layer.
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) | 1979-08-31 | 1980-03-01 | 1980-08-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-31 | 1984-03-01 | 1984-08-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-31 | 1988-03-01 | 1988-08-31 | $7700.00 | Window Closed / Lapsed |