Patent US3049001A successfully refreshed from Google Patents.
US3602838A
Expired / Lapsed
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Externally excited luminescent devices
Assignee: International Business Machines Corp
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Filing: 1968-07-18
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Granted: 1971-08-31
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Expires: 1988-07-18
Abstract
Abstract The disclosure provides a semiconductor luminescent device which is excited by either an electron beam or a photon beam. Particularly, a solid-state semiconductor laser element is formed of two layers, the first of which is a thin layer at the bombardment surface and the second of which is a thicker layer supporting the active layer. The first layer has a smaller energy gap than the second layer. The active layer must have a smaller energy gap than the inactive layer at the lasing wavelength. Because the active layer emits recombination radiation at a longer wavelength than the region of strong absorption in the inactive layer, there is a reduction in the energy loss in the inactive layer. Coherent emission or lasing perpendicular to the front surface is produced by introducing feedback via reflecting front and back surfaces, one or both of which may contain coatings to enhance their reflectivity.
Inventors
- 👤 Frank Stern
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:12
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/30; F; F21; F21K; F21K2/00; H01J; H01J29/00; H01J29/02; H01J29/10; H01J29/18; H01S3/00; H01S3/09; H01S3/0955; H01S3/0959
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
28 words
A luminescent device as set forth in claim 1 wherein reflecting layers are disposed on said two surfaces and amplification of said recombination radiation occurs in said material.
Claim 2
Dependent Claim
155 words
A luminescent device comprising: a solid-state semiconductor element having a front one surface and a back other surface approximately parallel thereto with varying composition of material therebetween such that the energy gap of said material proximate to said front surface is relatively smaller than the energy gap thereof proximate to said back surface and that recombination radiation generated proximate to said one surface is not absorbed significantly proximate to said other surface, the peak of the emission spectrum of said recombination radiation being at lower photon energies than the photon energies of relatively high absorption in the absorption spectrum of said material adjacent to said other surface; and an electron beam radiation source disposed to provide said electron beam to said one surface of said semiconductor element to generate said recombination radiation in said material having said relatively smaller energy gap; whereby said recombination radiation is emitted from said device preferentially perpendicularly to said surfaces.
Claim 3
Dependent Claim
37 words
A luminescent device as set forth in claim 3 wherein said electron beam source provides said electron beam with variable energy to select a given depth in said semiconductor element for generating said recombination radiation preferentially thereat.
Claim 4
Dependent Claim
49 words
A luminescent device as set forth in claim 3 wherein said varying composition results from one layer proximate to said one surface with a relatively small energy gap and from another layer bounding said one layer and being proximate to said other surface and having relatively large energy gap.
Claim 5
Dependent Claim
19 words
A luminescent device as set forth in claim 5 wherein said one layer has a gradient of composition therein.
Claim 6
Dependent Claim
35 words
A luminescent devices as set forth in claim 6 wherein electron beam source provides said electron beam with variable energy to select a given depth in said one layer for generating said recombination radiation thereat.
Claim 7
Dependent Claim
25 words
A luminescent device as set forth in claim 5 wherein said one layer consists of a plurality of other layers each with a different composition.
Claim 8
Dependent Claim
35 words
A luminescent device as set forth in claim 8 wherein said electron beam source provides said electron beam with variable energy to select one of said other layers for generating said recombination radiation preferentially therein.
Claim 9
Dependent Claim
145 words
A lasEr comprising: a source of an energetic radiation beam; a semiconductor element disposed in he path of said energetic radiation beam and having a first front layer coextensive with an active layer therein receptive of said beam and a second and inactive back layer beneath said front layer approximately parallel thereto, said front layer having relatively smaller energy gap than said back layer; first and second radiation reflective surfaces on said front and back layers respectively, said active layer providing stimulated recombination radiation generated through conversion therein of the energy of said energetic beam, the peak of the emission spectrum of said radiation in said front layer being at lower photon energies than the photon energies of relatively high absorption in the absorption spectrum of said back layer; whereby said stimulated recombination radiation is emitted from said laser device preferentially perpendicularly to said surfaces.
Claim 10
Dependent Claim
32 words
A laser device as set forth in claim 10 wherein said active layer has relatively small dimension in the direction of propagation of said radiation beam and relatively large dimension transverse thereto.
Claim 11
Dependent Claim
43 words
A laser device as set forth in claim 11 wherein said first layer and said second layer consist of the same semiconductor material with different dopant impurity concentrations such that said first layer has a smaller effective energy gap than said second layer.
Claim 12
Dependent Claim
23 words
A laser device as set forth in claim 12 wherein said second layer is N-type GaAs and said first layer is P-type GaAs.
Claim 13
Dependent Claim
20 words
A laser device as set forth in claim 13 wherein P-type GaAs is obtained by diffusion of acceptor dopant impurity.
Claim 14
Dependent Claim
16 words
A laser device as set forth in claim 14 wherein said P-type dopant impurity is Zn.
Claim 15
Dependent Claim
20 words
A laser device as set forth in claim 15 wherein said Zn in said GaAs is approximately 5 X 1018atoms/cm.
Claim 16
Dependent Claim
30 words
A laser device as set forth in claim 10 wherein said layers consist of Ga1 xAlxAs where said first layer has smaller x but x 0.4 in the first layer.
Claim 17
Dependent Claim
23 words
A laser device as set forth in claim 10 wherein said first layer is GaAs and said second layer Ga1 xAlxAs where x>0.
Claim 18
Dependent Claim
25 words
A laser device as set forth in claim 10 wherein said first layer consists of a checkerboard pattern disposed as islands in said second layer.
Claim 19
Dependent Claim
17 words
A laser device as set forth in claim 10 wherein said radiation beam is an electron beam.
Claim 20
Dependent Claim
26 words
A laser device as set forth in claim 20 wherein the energy of said electron beam is approximately the range of 30 kev. to 150 kev.
Claim 21
Dependent Claim
17 words
A laser device as set forth in claim 10 wherein said radiation beam is a photon beam.
Claim 22
Dependent Claim
21 words
A laser device as set forth in claim 10 wherein said second layer does not absorb significantly said stimulated recombination radiation.
Claim 23
Dependent Claim
34 words
A laser device as set forth in claim 10 wherein said stimulated recombination radiation in the direction perpendicular to the first layer is encouraged and propagation thereof parallel to the first layer is discouraged.
Claim 24
Dependent Claim
26 words
A laser device as set forth in claim 10 wherein the thickness of said active layer is approximately in the range of 1 to 20 microns.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-08-30 | 1975-03-01 | 1975-08-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-30 | 1979-03-01 | 1979-08-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-30 | 1983-03-01 | 1983-08-31 | $7700.00 | Window Closed / Lapsed |