Patent US4807241A successfully refreshed from Google Patents.
US4807241A
Expired / Lapsed
US
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Electron beam pumped laser
Assignee: Nokia Bell Labs
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Filing: 1987-07-10
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Granted: 1989-02-21
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Expires: 2007-07-10
Abstract
Abstract The luminescent screen of a cathode ray tube includes an array of monocrystalline or amorphous phosphor rod-like elements which are covered with a reflective coating except for one end of each element which serves as an output face. The phenomenon of the light trapping is advantageously exploited to achieve enhanced brightness. The screen is illuminated with an electron beam which has an essentially oblong cross section and which is oriented along the elongated dimension of the elements. In one embodiment the elements comprise epitaxial Lu 3 Al 3 Ga 2 O 12 :Ce on the top of a YAG substrate, and a light absorbing layer of Lu 3 Al 3 .5 Fe 1 .5 O 12 is formed on the bottom of the substrate. A printer utilizing such a CRT is described. Also described is a configuration in which each of the rod-like elements functions as a laser.
Inventors
- 👤 George W. Berkstresser
- 👤 Joseph Shmulovich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:20
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/02; H01J29/10; H01J29/18; H01J29/28; C; C09; C09K; C09K11/00; C09K11/08; C09K11/77; C09K11/7766; C09K11/7774; H01J29/20; H01J29/24
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
124 words
Optical apparatus comprising an elongated element including a laser active medium and a conversion layer optically coupled to said medium, said active medium comprising (Y 3-x-y R x Lu y )(Al 5-w Ga w )O 12 , with R chosen from the group consisting of the lanthanide rare earth elements other than Lu and Y, and 0<x<0.3, 1.5<w<2.5, and y=1.4w±0.4w. means forming an optical resonator including said element therein, and means for generating an electron beam having an essentially oblong cross section which is made incident along the elongated dimension of said element, said electron beam being absorbed in said conversion layer so as to generate optical radiation which is absorbed in said active medium, thereby to produce stimulated emission from said active medium.
Claim 2
Dependent Claim
124 words
Optical apparatus comprising an elongated element including a laser active medium and a conversion layer optically coupled to said medium, said active medium comprising (Y 3-x-y R x Lu y )(Al 5-w Ga w )O 12 , with R chosen from the group consisting of the lanthanide rare earth elements other than Lu and Y, and 0<x<0.3, 1.5<w<2.5, and y=1.4w±0.4w. means forming an optical resonator including said element therein, and means for generating an electron beam having an essentially oblong cross section which is made incident along the elongated dimension of said element, said electron beam being absorbed in said conversion layer so as to generate optical radiation which is absorbed in said active medium, thereby to produce stimulated emission from said active medium.
Claim 3
Dependent Claim
32 words
The apparatus of claim 1 wherein said element has the shape of a rod and said resonator forming means includes a pair of parallel mirrors formed on opposite ends of said rod.
Claim 4
Dependent Claim
42 words
The apparatus of claim 2 including a plurality of said elements arranged parallel to one another and wherein said generating means includes means for scanning said electron beam across selected ones of said elements, thereby to produce a scanning spot of light.
Claim 5
Dependent Claim
113 words
Optical apparatus comprising an elongated element including a laser active medium and a conversion layer optically coupled to said medium, said active medium comprising Y 3 Al 5 O 12 doped with Nd and Cr and said conversion layer comprising Y 3 Al 5 O 12 doped with Ce, means forming an optical resonator including said element therein, and means for generating an electron beam having an essentially oblong cross section which is made incident along the elongated dimension of said element, said electron beam being absorbed in said conversion layer so as to generate optical radiation which is absorbed in said active medium, thereby to produce stimulated emission from said active medium.
Claim 6
Dependent Claim
113 words
Optical apparatus comprising an elongated element including a laser active medium and a conversion layer optically coupled to said medium, said active medium comprising Y 3 Al 5 O 12 doped with Nd and Cr and said conversion layer comprising Y 3 Al 5 O 12 doped with Ce, means forming an optical resonator including said element therein, and means for generating an electron beam having an essentially oblong cross section which is made incident along the elongated dimension of said element, said electron beam being absorbed in said conversion layer so as to generate optical radiation which is absorbed in said active medium, thereby to produce stimulated emission from said active medium.
Claim 7
Dependent Claim
32 words
The apparatus of claim 4 wherein said element has the shape of a rod and said resonator forming means inclues a pair of parallel mirrors formed on opposite ends of said rod.
Claim 8
Dependent Claim
42 words
The apparatus of claim 5 including a plurality of said elements arranged parallel to one another and wherein said generating means includes means for scanning said electron beam across selected ones of said elements, thereby to produce a scanning spot of light.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-02-21 | 1992-08-22 | 1993-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-02-21 | 1996-08-22 | 1997-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-02-21 | 2000-08-22 | 2001-02-21 | $7700.00 | Window Closed / Lapsed |