US5072120A
Expired / Lapsed
US
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Electromagnetic imager device
Assignee: Applied Systems Corp
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Filing: 1989-02-09
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Granted: 1991-12-10
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Expires: 2009-02-09
Abstract
Abstract An electromagnetic imager device can detect electromagnetic images, for example, in the infrared, millimeter and microwave wavelengths and convert these images into useful wavelengths which imaging devices, such as a camera, can record. The electromagnetic imager includes an interferometer having one arm thereof filled with a gaseous mixture. The particular gaseous mixture used, improves the accuracy of the device by enhancing the probability of an exchange of kinetic energy for molecular internal energy during molecular collision. The electromagnetic image is absorbed in an internal mode of the molecular species in the gas over an absorption depth. The absorption of the electromagnetic energy causes heating in the gas which, in turn, causes local changes in the index of refraction in the focal plane of the gas. These changes in the index of refraction phase modulate the phase front of the laser beam passing through the gas. The local index of refraction variations thus result in a direct mapping of the absorbed electromagnetic energy image allowing the image to be detected by interferometric means.
Inventors
- 👤 Joseph T. Siewick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 21:55
CPC Classifications
G; G01; G01J; G01J5/00; G01J5/38; G01J5/42; G01J9/00; G01J9/02
Claims Analysis
Total Claims: 60
Claim 1
Independent Claim
130 words
A method of converting real images of a predetermined range of electromagnetic frequencies to a variation of the index of refraction of predetermined fluid media in a focal plane within said media by disposing an electromagnetic image in a predetermined fluid medium to allow electromagnetic radiation from the image to be absorbed by the medium by direct mapping into the medium in proportion to the local amount of electromagnetic radiation absorbed from corresponding points in the image resulting from excitation of internal molecular energy modes of the molecular species causing a variation of the index of refraction of the medium in the focal plane corresponding to the image, said method including the steps of containing said fluid media in an interferometer, and passing a laser beam through said fluid media.
Claim 2
Independent Claim
130 words
A method of converting real images of a predetermined range of electromagnetic frequencies to a variation of the index of refraction of predetermined fluid media in a focal plane within said media by disposing an electromagnetic image in a predetermined fluid medium to allow electromagnetic radiation from the image to be absorbed by the medium by direct mapping into the medium in proportion to the local amount of electromagnetic radiation absorbed from corresponding points in the image resulting from excitation of internal molecular energy modes of the molecular species causing a variation of the index of refraction of the medium in the focal plane corresponding to the image, said method including the steps of containing said fluid media in an interferometer, and passing a laser beam through said fluid media.
Claim 3
Dependent Claim
135 words
An electromagnetic imager for converting real images of a predetermined range of electromagnetic frequencies to a variation of the index of refraction of predetermined fluid media in a focal plane within said media comprising: a predetermined fluid medium; and means for disposing an electromagnetic image in said predetermined medium and allowing electromagnetic radiation from the image to be absorbed by the medium by direct mapping into the medium in proportion to the local amount of electromagnetic radiation absorbed from corresponding points in the image resulting from excitation of internal molecular energy modes of the molecular species causing a variation of the index of refraction of the medium in the focal plane corresponding to the image, said electromagnetic imager including an interferometer, and said fluid medium being disposed in at least a portion of said interferometer.
Claim 4
Dependent Claim
135 words
An electromagnetic imager for converting real images of a predetermined range of electromagnetic frequencies to a variation of the index of refraction of predetermined fluid media in a focal plane within said media comprising: a predetermined fluid medium; and means for disposing an electromagnetic image in said predetermined medium and allowing electromagnetic radiation from the image to be absorbed by the medium by direct mapping into the medium in proportion to the local amount of electromagnetic radiation absorbed from corresponding points in the image resulting from excitation of internal molecular energy modes of the molecular species causing a variation of the index of refraction of the medium in the focal plane corresponding to the image, said electromagnetic imager including an interferometer, and said fluid medium being disposed in at least a portion of said interferometer.
Claim 5
Dependent Claim
16 words
An electromagnetic imager as recited in claim 2, wherein the predetermined medium is a liquid medium.
Claim 6
Dependent Claim
16 words
An electromagnetic imager as recited in claim 2, wherein said predetermined medium is a gaseous medium.
Claim 7
Dependent Claim
25 words
An electromagnetic imager as recited in claim 2, wherein said predetermined range of electromagnetic frequencies includes radiation in the infrared portion of the electromagnetic spectrum.
Claim 8
Dependent Claim
26 words
An electromagnetic imager as recited in claim 2, wherein said predetermined range of electromagnetic frequencies includes radiation in the millimeter wave portion of the electromagnetic spectrum.
Claim 9
Dependent Claim
25 words
An electromagnetic imager as recited in claim 2, wherein said predetermined range of electromagnetic frequencies includes radiation in the microwave portion of the electromagnetic spectrum.
Claim 10
Dependent Claim
15 words
An electromagnetic imager as recited in claim 2, wherein said interferometer is a Mach-Zehnder interferometer.
Claim 11
Dependent Claim
15 words
An electromagnetic imager as recited in claim 2, wherein said interferometer is a Michelson interferometer.
Claim 12
Dependent Claim
15 words
An electromagnetic imager as recited in claim 2, wherein said interferometer is a Fabry-Perot interferometer.
Claim 13
Dependent Claim
62 words
An electromagnetic imager comprising: a fluid medium; and means for converting real images at a predetermined electromagnetic wavelength to a variation of the refractive index of the medium in the focal plane of the medium in direct correspondence to the real image, said electromagnetic imager including an interferometer, and said fluid medium being disposed in at least a portion of said interferometer.
Claim 14
Dependent Claim
62 words
An electromagnetic imager comprising: a fluid medium; and means for converting real images at a predetermined electromagnetic wavelength to a variation of the refractive index of the medium in the focal plane of the medium in direct correspondence to the real image, said electromagnetic imager including an interferometer, and said fluid medium being disposed in at least a portion of said interferometer.
Claim 15
Independent Claim
124 words
A device for converting real images of a predetermined range of electromagnetic frequencies to a variation of the index of refraction of predetermined mediums in the focal plane of the medium comprising: a predetermined medium; and means for disposing an electromagnetic image proximate said predetermined medium and allowing electromagnetic radiation from the image to be absorbed by the medium by direct mapping into the medium in proportion to the local amount of electromagnetic radiation absorbed from corresponding points in the image resulting from excitation of internal molecular energy modes of the molecular species causing a variation of the index of refraction in the focal plane of the medium corresponding to the image, and means for enhancing the probability of energy exchange upon molecular collisions.
Claim 16
Independent Claim
124 words
A device for converting real images of a predetermined range of electromagnetic frequencies to a variation of the index of refraction of predetermined mediums in the focal plane of the medium comprising: a predetermined medium; and means for disposing an electromagnetic image proximate said predetermined medium and allowing electromagnetic radiation from the image to be absorbed by the medium by direct mapping into the medium in proportion to the local amount of electromagnetic radiation absorbed from corresponding points in the image resulting from excitation of internal molecular energy modes of the molecular species causing a variation of the index of refraction in the focal plane of the medium corresponding to the image, and means for enhancing the probability of energy exchange upon molecular collisions.
Claim 17
Dependent Claim
26 words
A device as recited in claim 12, wherein said enhancing means includes a gaseous mixture that includes an absorbing molecular species and a collider molecular species.
Claim 18
Dependent Claim
16 words
A device as recited in claim 13, wherein said collider species is a slow collider species.
Claim 19
Dependent Claim
22 words
A device as recited in claim 14 wherein said slow collider species is selected from the group consisting of argon and neon.
Claim 20
Dependent Claim
16 words
A device as recited in claim 14, wherein said collider species is a fast collider species.
Claim 21
Dependent Claim
22 words
A device as recited in claim 16, wherein said fast collider species is selected from the group consisting of helium and hydrogen.
Claim 22
Dependent Claim
16 words
A device as recited in claim 13, wherein said absorbing molecular species is SF 6 .
Claim 23
Dependent Claim
20 words
A device as recited in claim 12, wherein said enhancing means includes means for increasing the pressure of said medium.
Claim 24
Dependent Claim
14 words
A device as recited in claim 13, wherein said absorbing molecular species is oxygen.
Claim 25
Dependent Claim
36 words
A device as recited in claim 13, wherein said absorbing molecular species is selected from the group consisting of carbon monoxide, carbon dioxide, dinitrogen oxide, hydrogen cyanide, nitrous oxide, hydrogen sulfide, hydrogen deuterium sulfide or formaldehyde.
Claim 26
Dependent Claim
37 words
A device as recited in claim 13, wherein said absorbing molecular species is selected from the group consisting of hydrogen cyanide, ammonia, phosphine, trifluorophine, stibine, methyl flouride, methyl chloride, methyl bromide, methyl iodide, carbon oxysulfide or phosphorotrichloridothioate.
Claim 27
Dependent Claim
119 words
An electromagnetic imager comprising: an interferometer having a portion thereof filled with a fluid medium for absorbing electromagnetic radiation including an electromagnetic radiation input window for receiving laser light from a laser: control means for maintaining said laser proximate its linear response region; a beam splitter for splitting the laser light into two paths A and B of relatively equal intensity, a recombining beam splitter and at least one output port; said fluid medium being selected for absorbing electromagnetic radiation in a predetermined range of frequencies; wherein radiation from said electromagnetic image of interest is absorbed by said medium causing variation in the index of refraction proximate the focal plane of said fluid medium corresponding to said electromagnetic image.
Claim 28
Dependent Claim
119 words
An electromagnetic imager comprising: an interferometer having a portion thereof filled with a fluid medium for absorbing electromagnetic radiation including an electromagnetic radiation input window for receiving laser light from a laser: control means for maintaining said laser proximate its linear response region; a beam splitter for splitting the laser light into two paths A and B of relatively equal intensity, a recombining beam splitter and at least one output port; said fluid medium being selected for absorbing electromagnetic radiation in a predetermined range of frequencies; wherein radiation from said electromagnetic image of interest is absorbed by said medium causing variation in the index of refraction proximate the focal plane of said fluid medium corresponding to said electromagnetic image.
Claim 29
Dependent Claim
15 words
An electromagnetic imager as recited in claim 23, wherein said interferometer is a Mach-Zehnder interferometer.
Claim 30
Dependent Claim
15 words
An electromagnetic imager as recited in claim 23, wherein said medium is a gaseous medium.
Claim 31
Dependent Claim
15 words
An electromagnetic imager as recited in claim 23, wherein said interferometer is a Michelson interferometer.
Claim 32
Dependent Claim
15 words
An electromagnetic imager as recited in claim 23, wherein said interferometer is a Fabry-Perot interferometer.
Claim 33
Dependent Claim
132 words
An electromagnetic imager comprising: an interferometer filled with a gaseous medium for absorbing electromagnetic radiation including an electromagnetic input window for receiving an electromagnetic image; an input port for receiving laser light from a laser; control means for maintaining said laser in its linear response region; a beam splitter for splitting the laser light into two paths A and B of relatively equal intensity, a recombining beam splitter and one or more output ports; said interferometer filled with a medium for absorbing electromagnetic radiation in a predetermined range of frequencies; wherein radiation from said electromagnetic image of interest is absorbed by said medium causing variations in the index of refraction in the focal plane of the gaseous medium corresponding to said electromagnetic image, wherein said interferometer is provided with two output ports.
Claim 34
Dependent Claim
132 words
An electromagnetic imager comprising: an interferometer filled with a gaseous medium for absorbing electromagnetic radiation including an electromagnetic input window for receiving an electromagnetic image; an input port for receiving laser light from a laser; control means for maintaining said laser in its linear response region; a beam splitter for splitting the laser light into two paths A and B of relatively equal intensity, a recombining beam splitter and one or more output ports; said interferometer filled with a medium for absorbing electromagnetic radiation in a predetermined range of frequencies; wherein radiation from said electromagnetic image of interest is absorbed by said medium causing variations in the index of refraction in the focal plane of the gaseous medium corresponding to said electromagnetic image, wherein said interferometer is provided with two output ports.
Claim 35
Dependent Claim
27 words
An electromagnetic imager as recited in claim 28, wherein a positive image is produced at one output port and a negative image at the other output port.
Claim 36
Dependent Claim
73 words
An electromagnetic imager as recited in claim 29, wherein said output port, containing said positive image, illuminates a first detector array through a first relay lens and said output port, containing said negative image, illuminates a second detector array through a second relay lens; said first detector array coupled to a non-inverting amplifier and said second detector array coupled to an inverting amplifier; the outputs of said amplifiers coupled to a summing amplifier.
Claim 37
Dependent Claim
16 words
An electromagnetic imager as recited in claim 23, further including means for detecting said real image.
Claim 38
Dependent Claim
16 words
An electromagnetic imager as recited in claim 31, wherein said detecting means includes a vidicon tube.
Claim 39
Dependent Claim
16 words
An electromagnetic imager as recited in claim 31, wherein said detecting means includes a detector array.
Claim 40
Dependent Claim
15 words
An electromagnetic imager as recited in claim 31, wherein said detecting means includes a camera.
Claim 41
Dependent Claim
29 words
An electromagnetic imager as recited in claim 23, further including a screen in communication with said output port of said interferometer; wherein said real image is on said screen.
Claim 42
Dependent Claim
16 words
An electromagnetic imager as recited in claim 35, further including means for detecting said real image.
Claim 43
Dependent Claim
16 words
An electromagnetic imager as recited in claim 35, wherein said detecting means includes a vidicon tube.
Claim 44
Dependent Claim
16 words
An electromagnetic imager as recited in claim 35, wherein said detecting means includes a detector array.
Claim 45
Dependent Claim
15 words
An electromagnetic imager as recited in claim 35, wherein said detecting means includes a camera.
Claim 46
Dependent Claim
89 words
A night vision device comprising an interferometer filled with a fluid medium for absorbing electromagnetic radiation having an electromagnetic image input window, an input port for receiving laser light from a laser, a beam splitter for splitting the laser light into two paths A and B of relatively equal intensity, an output port nd a screen disposed adjacent said output port, wherein any electromagnetic image in said predetermined frequency range applied to said electromagnetic image input window will be displayed on said screen and observable by a human eye.
Claim 47
Dependent Claim
89 words
A night vision device comprising an interferometer filled with a fluid medium for absorbing electromagnetic radiation having an electromagnetic image input window, an input port for receiving laser light from a laser, a beam splitter for splitting the laser light into two paths A and B of relatively equal intensity, an output port nd a screen disposed adjacent said output port, wherein any electromagnetic image in said predetermined frequency range applied to said electromagnetic image input window will be displayed on said screen and observable by a human eye.
Claim 48
Dependent Claim
20 words
A night vision device as recited in claim 40, further including relaying optics disposed adjacent said electromagnetic image input window.
Claim 49
Dependent Claim
21 words
A night vision device as recited in claim 40, further including means for maintaining said interferometer in its linear response region.
Claim 50
Dependent Claim
23 words
A night vision device as recited in claim 40, wherein said electromagnetic radiation absorbing medium is a gaseous medium having a fixed volume.
Claim 51
Dependent Claim
19 words
A night vision device as recited in claim 40, wherein said predetermined frequency range includes the infrared frequency range.
Claim 52
Independent Claim
102 words
A device for imaging electromagnetic radiation in a predetermined frequency range into an analog optical computer comprising: a laser; an interferometer including an electromagnetic image receiving window for receiving an electromagnetic image from an input port for receiving laser light from said laser and an output port; said interferometer filled with a fluid medium for absorbing electromagnetic radiation in a predetermined frequency range; a Fourier transform lens disposed adjacent said output port for producing a Fourier transform of the image; and an inverse Fourier transform lens disposed adjacent said Fourier transform lens for providing an input signal to an optical analog computer.
Claim 53
Independent Claim
102 words
A device for imaging electromagnetic radiation in a predetermined frequency range into an analog optical computer comprising: a laser; an interferometer including an electromagnetic image receiving window for receiving an electromagnetic image from an input port for receiving laser light from said laser and an output port; said interferometer filled with a fluid medium for absorbing electromagnetic radiation in a predetermined frequency range; a Fourier transform lens disposed adjacent said output port for producing a Fourier transform of the image; and an inverse Fourier transform lens disposed adjacent said Fourier transform lens for providing an input signal to an optical analog computer.
Claim 54
Dependent Claim
18 words
A device as recited in claim 45, wherein said electromagnetic radiation frequency range includes the infrared frequency range.
Claim 55
Dependent Claim
18 words
A device as recited in claim 45, wherein said electromagnetic frequency range includes the millimeter wave frequency range.
Claim 56
Dependent Claim
17 words
A device as recited in claim 45, wherein said electromagnetic frequency range includes the microwave frequency range.
Claim 57
Dependent Claim
23 words
A device as recited in claim 45, further including a matched spatial filter, disposed at the focal plane of said Fourier transform lens.
Claim 58
Dependent Claim
19 words
A device as recited in claim 45, further including a relay lens disposed adjacent said electromagnetic energy input window.
Claim 59
Dependent Claim
20 words
A device as recited in claim 45, further including control means for maintaining said interferometer in its linear response region.
Claim 60
Dependent Claim
14 words
A device as recited in claim 45, wherein said medium includes a gaseous mixture.
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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) | 1994-12-09 | 1995-06-10 | 1995-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-09 | 1999-06-10 | 1999-12-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-09 | 2003-06-10 | 2003-12-10 | $7700.00 | Window Closed / Lapsed |