US4020341A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Generating and using coherent optical radiation
Assignee: Massachusetts Institute of Technology
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Filing: 1975-09-11
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Granted: 1977-04-26
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Expires: 1995-09-11
Abstract
Abstract Optical radiation generation and detection using metal-to-metal diode junctions. Coherent optical radiation is generated by using an antenna connected to a metal-to-metal diode junction with non-linear current-voltage characteristics and by coupling to the junction electromagnetic radiation energy to interact with the junction, causing emission from the antenna at optical frequency absent from the input. Optical diodes are shown in the forms of a mechanically contacted cat whisker system and as single and multiple microscopic solid portions in an integrated solid mass, defining both the antenna and the junction, preferably as a deposit of solid layers upon a substrate, preferably as overlapping printed circuit line structures. Arrays of such junctions provide enhanced effects; useful arrays include Franklin-Marconi geometries, fish-bone antennas and row and column arrays. Such solid diode constructions and arrays thereof are used not only for optical radiation generation but also detection and mixing including use in an image scanner, energy converter and a broad band detector. The diodes as a radiation source are used in combination with an absorbtion cell in spectroscopic analysis, a feedback loop in a stable frequency source, and an optical frequency communicating system.
Inventors
- 👤 Ali Javan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 09:57
CPC Classifications
G; G02; G02F; G02F2/00; G02F2/002; H; H10; H10D; H10D99/00; H10N; H10N70/00
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
86 words
A method for generating coherent optical radiation comprising providing an antenna connected to a metal-to-metal diode junction having non-linear characteristics, and coupling to said diode junction an input of electromagnetic energy sufficient to interact with said junction to cause generation of current through said junction, causing flow of said current in said antenna, and causing resultant emission of coherent radiation from said antenna, said current and radiation being of an optical frequency which is dependent upon the frequency of said input and absent from said input.
Claim 2
Independent Claim
86 words
A method for generating coherent optical radiation comprising providing an antenna connected to a metal-to-metal diode junction having non-linear characteristics, and coupling to said diode junction an input of electromagnetic energy sufficient to interact with said junction to cause generation of current through said junction, causing flow of said current in said antenna, and causing resultant emission of coherent radiation from said antenna, said current and radiation being of an optical frequency which is dependent upon the frequency of said input and absent from said input.
Claim 3
Dependent Claim
26 words
The method of claim 1 wherein said diode junction is provided by a metal cat whisker with a pointed end in contact with a metal base.
Claim 4
Dependent Claim
42 words
The method of claim 1 wherein said diode junction is provided by solid deposits of two metal layers having a limited common area at which the metals are separated by a dielectric forming in effect a metal-to-metal junction with non-linear current-voltage characteristics.
Claim 5
Dependent Claim
26 words
A method as claimed in claim 1 comprising collecting said radiation of said optical frequency emitted from said antenna for direction to a station of utilization.
Claim 6
Dependent Claim
22 words
A method as claimed in claim 1 wherein said input comprises radiation of optical frequency coupled to said junction through said antenna.
Claim 7
Dependent Claim
18 words
A method as claimed in claim 1, wherein said input comprises a component frequency in the microwave range.
Claim 8
Dependent Claim
22 words
A method as claimed in claim 6 including varying said microwave frequency so that said emitted optical radiation has a desired frequency.
Claim 9
Dependent Claim
29 words
A method as claimed in claim 7, said microwave frequency being modulated by an information bearing signal, thereby causing said emitted optical radiation to be modulated by said signal.
Claim 10
Dependent Claim
26 words
A method as claimed in claim 1, said emitted radiation being produced by even order mixing, and including applying a d.c. biasing voltage across said junction.
Claim 11
Dependent Claim
19 words
A method as claimed in claim 2, said pointed end having a radius of curvature less than 50 nm.
Claim 12
Dependent Claim
21 words
A method as claimed in claim 2, said cat whisker having a diameter smaller than the wavelength of said emitted radiation.
Claim 13
Dependent Claim
101 words
Apparatus for generating coherent optical radiation comprising at least one antenna connected to a diode junction having non-linear characteristics, a source of electromagnetic energy coupled to said diode junction to interact with said junction to cause generation of a current through said junction, flow of said current through said antenna and emission of radiation from said antenna, said current and radiation being of optical frequency which is related to the frequency of the input and absent from the input, an optical element for collecting said radiation of said optical frequency emitted from said antenna for direction to a station for utilization.
Claim 14
Dependent Claim
101 words
Apparatus for generating coherent optical radiation comprising at least one antenna connected to a diode junction having non-linear characteristics, a source of electromagnetic energy coupled to said diode junction to interact with said junction to cause generation of a current through said junction, flow of said current through said antenna and emission of radiation from said antenna, said current and radiation being of optical frequency which is related to the frequency of the input and absent from the input, an optical element for collecting said radiation of said optical frequency emitted from said antenna for direction to a station for utilization.
Claim 15
Dependent Claim
21 words
Apparatus as claimed in claim 12, said source providing a component of electromagnetic energy with a frequency in the microwave range.
Claim 16
Dependent Claim
15 words
Apparatus as claimed in claim 13, further comprising means for controllably varying said microwave frequency.
Claim 17
Dependent Claim
22 words
Apparatus as claimed in claim 14, including controls for adjusting said microwave frequency so that said emitted radiation has a desired frequency.
Claim 18
Dependent Claim
27 words
Apparatus as claimed in claim 14, including means for modulating said mocrowave frequency by an information bearing signal, whereby said emitted radiation is modulated by said signal.
Claim 19
Dependent Claim
20 words
Apparatus as claimed in claim 12, said diode junction including a cat whisker with a pointed end contacting a base.
Claim 20
Dependent Claim
12 words
Apparatus as claimed in claim 17, said base being made of nickel.
Claim 21
Dependent Claim
27 words
Apparatus as claimed in claim 12, said emitted radiation being produced by even order mixing, and including a source of d.c. biasing voltage applied across said junction.
Claim 22
Dependent Claim
18 words
Apparatus as claimed in claim 17 said pointed end having a radius of curvature less than 50 nm.
Claim 23
Dependent Claim
20 words
Apparaus as claimed in claim 17, said cat whisker having a diameter smaller than the wavelength of said emitted radiation.
Claim 24
Dependent Claim
29 words
Apparatus as claimed in claim 15, said control for said microwave frequency including a feedbacck loop connected through said diode to stabilize the frequency of said emitted optical radiation.
Claim 25
Dependent Claim
150 words
Apparatus according to claim 12 comprising a solid substrate, a solid metal deposit thereon, a solid dielectric layer upon a portion of said metal deposit, and a second solid metal deposit on said substrate, said second metal deposit having a predetermined limited common area with said first metal deposit, the respective common portions of said metal deposits being in intimate contact with opposite sides of and separated by said dielectric layer, said dielectric layer being of limited thickness, said common region thereby defining a potential barrier producing a metal-to-metal junction with nonlinear voltage current characteristics, a portion of one of said metal deposits extending away from said common region having a width related to the wave length of said optical radiation and, forming an antenna responsive to said incident radiation to generate an alternating electrical current at the frequency of said radiation, and to conduct said current to said junction.
Claim 26
Dependent Claim
48 words
The apparatus according to claim 23 wherein said dielectric layer is of the order of 1 manometer or less thickness, said metal deposits and interposed dielectric layer chosen to provide a barrier potential enabling quantum mechanical electron tunneling accross the said potential barrier to predominantly determine junction impedance.
Claim 27
Dependent Claim
131 words
Apparatus for generating optical radiation comprising an array of devices formed on a substrate transparent to the generated radiation, each device including an antenna connected to a diode junction having non-linear current-voltage characteristics, each of said devices including an elongated deposit of a first conductive material, a dielectric layer contacting a portion of said deposit, and a deposit of a second conductive material contacting said dielectric material close to said elongated deposit, the devices in said array being disposed to give cooperative directional radiation, a source of electromagnetic energy coupled to the junctions of said array to cause generation of currents in said junctions, flow of said currents through said antennas and emission radiation from said antennas, said currents and radiationn being of optical frequency absent from inputs to the devices.
Claim 28
Dependent Claim
131 words
Apparatus for generating optical radiation comprising an array of devices formed on a substrate transparent to the generated radiation, each device including an antenna connected to a diode junction having non-linear current-voltage characteristics, each of said devices including an elongated deposit of a first conductive material, a dielectric layer contacting a portion of said deposit, and a deposit of a second conductive material contacting said dielectric material close to said elongated deposit, the devices in said array being disposed to give cooperative directional radiation, a source of electromagnetic energy coupled to the junctions of said array to cause generation of currents in said junctions, flow of said currents through said antennas and emission radiation from said antennas, said currents and radiationn being of optical frequency absent from inputs to the devices.
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) | 1980-04-25 | 1980-10-25 | 1981-04-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-25 | 1984-10-25 | 1985-04-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-25 | 1988-10-25 | 1989-04-26 | $7700.00 | Window Closed / Lapsed |