Patent US3890503A successfully refreshed from Google Patents.
US3890503A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stimulated emission light source pumped by electron beam of field emission initiated vacuum arc
Assignee: HP Inc
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Filing: 1971-05-28
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Granted: 1975-06-17
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Expires: 1991-05-28
Abstract
Abstract An apparatus for generating stimulated emission light pulses of extremely high power up to 5 megawatts by electron beam pumping of laser type light emitting material, is described which employs an electron beam of extremely high current up to 6000 amperes at 450 kiloelectron-volts produced by field emission initiated vacuum arc operation of an electron tube having a field emission cathode. The field emission cathode structure has a plurality of separate needle shaped emitting elements. The laser material is mounted either on an anode inside the evacuated tube envelope or outside of the envelope adjacent an electron transparent anode window. Coherent light may be produced by causing oscillation of the light in an optical resonant cavity provided by a pair of parallel mirrors on opposite sides of the laser material.
Inventors
- 👤 John L Brewster
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 07:05
CPC Classifications
H; H01; H01J; H01J3/00; H01J3/02; H01J3/021; H01J33/00; H01S; H01S3/00; H01S3/09; H01S3/0955; H01S3/0959
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
209 words
Apparatus for generating high intensity light pulses comprising: light source means including particulate light emitting material capable of producing light by stimulated emission of radiation, said light emitting material being supported on an electrically conductive support member; an evacuated envelope containing no appreciable free gas; means for mounting said light emitting material outside said envelope; electron pumping means including an anode, and a field emission cathode having at least one sharpened emitting element mounted within said envelope, for emitting a beam of electrons through the anode to the exterior of the envelope and for bombarding the light emitting material with said electrons to cause said material to emit light; and pulser means for applying narrow electrical pulses between said cathode and said anode which are each of sufficiently high voltage and high current to cause the field emission of electrons from the cathode emitting element and evaporation of a portion of said emitting element to form free ions of cathode material which produce a vacuum arc within the envelope, said vacuum arc causing an extremely high electron beam current to flow from said cathode to the particles of light emitting material so that a light pulse of high intensity is emitted by stimulated emission of radiation from said material.
Claim 2
Dependent Claim
209 words
Apparatus for generating high intensity light pulses comprising: light source means including particulate light emitting material capable of producing light by stimulated emission of radiation, said light emitting material being supported on an electrically conductive support member; an evacuated envelope containing no appreciable free gas; means for mounting said light emitting material outside said envelope; electron pumping means including an anode, and a field emission cathode having at least one sharpened emitting element mounted within said envelope, for emitting a beam of electrons through the anode to the exterior of the envelope and for bombarding the light emitting material with said electrons to cause said material to emit light; and pulser means for applying narrow electrical pulses between said cathode and said anode which are each of sufficiently high voltage and high current to cause the field emission of electrons from the cathode emitting element and evaporation of a portion of said emitting element to form free ions of cathode material which produce a vacuum arc within the envelope, said vacuum arc causing an extremely high electron beam current to flow from said cathode to the particles of light emitting material so that a light pulse of high intensity is emitted by stimulated emission of radiation from said material.
Claim 3
Dependent Claim
29 words
An apparatus in accordance with claim 1 in which the field emission cathode includes a plurality of separate sharpened emitting elements which are substantially uniformly spaced from the anode.
Claim 4
Dependent Claim
38 words
An apparatus in accordance with claim 1 in which the pulser means produces electrical pulses which terminate before any ions of evaporated anode material which may be produced due to electron bombardment, can bE transmitted to the cathode.
Claim 5
Dependent Claim
17 words
An apparatus in accordance with claim 2 in which the support member forms part of the anode.
Claim 6
Dependent Claim
38 words
An apparatus in accordance with claim 1 in which the light emitting material and support members are separate from the anode, and the anode is an electron transparent member which is mounted between said material and the cathode.
Claim 7
Dependent Claim
43 words
An apparatus in accordance with claim 5 in which the anode is a thin sheet of metal forming an electron window in the envelope wall and the light emitting material is mounted on the support member outside the envelope adjacent the electron window.
Claim 8
Dependent Claim
16 words
An apparatus in accordance with claim 1 in which the light emitting material is semiconductor material.
Claim 9
Dependent Claim
23 words
An apparatus in accordance with claim 2 in which the cathode emitting elements are in the form of a plurality of pointed needles.
Claim 10
Dependent Claim
31 words
An apparatus in accordance with claim 8 in which the cathode needles are supported in a plurality of annular arrays of substantially the same diameter which are concentric with the anode.
Claim 11
Dependent Claim
22 words
An apparatus in accordance with claim 6 in which the support member is a thin electron transparent foil of light reflecting metal.
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) | 1978-06-16 | 1978-12-16 | 1979-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-16 | 1982-12-16 | 1983-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-16 | 1986-12-16 | 1987-06-17 | $7700.00 | Window Closed / Lapsed |