US3640604A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical information processing method employing photochemically generated holograms as spatial filters
Assignee: Hawker Siddeley Dynamics Ltd
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Filing: 1970-05-01
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Granted: 1972-02-08
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Expires: 1990-05-01
Abstract
Abstract This invention provides a novel method of optical information processing, using a photochromically generated hologram as a spatial filter. A diffraction pattern is produced on a photochromic plate which is simultaneously illuminated by a reference beam from a coherent source. A second diffraction pattern employing light from a coherent source is superimposed on the first diffraction pattern on the photochromic plate, so that the reference beam illumination and the second diffraction pattern form a photochromically generated hologram to modify the first diffraction pattern. A photochromic plate may comprise material that exhibits normally unpopulated triplet states of molecular energy, population of which can be induced by photons of appropriate energy.
Inventors
- 👤 John Yarnell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 00:34
CPC Classifications
G; G03; G03H; G03H1/00; G03H1/0005; G02; G02B; G02B27/00; G02B27/42; G02B27/46; G03H1/02; G03H1/04; G03H1/16; G03H2001/0066; G03H2260/00; G03H2260/30; G03H2260/35; G03H2260/36; G03H2260/50; G03H2260/52
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
120 words
A method of processing optical information, using a hologram as a spatial filter, comprising producing a first diffraction pattern on a photochromic plate by illumination of an object disposed in a beam of coherent light which is uncollimated, simultaneously illuminating the photochromic plate by a reference beam from a coherent source of light of a frequency different from that employed in the production of said first diffraction pattern and lying substantially entirely within the visible spectrum, and superimposing a second diffraction pattern employing light from said coherent source of visible light on said first diffraction pattern on said photochromic plate, whereby the reference beam illumination and said diffraction pattern form a photochromically generated hologram to modify said first diffraction pattern.
Claim 2
Independent Claim
120 words
A method of processing optical information, using a hologram as a spatial filter, comprising producing a first diffraction pattern on a photochromic plate by illumination of an object disposed in a beam of coherent light which is uncollimated, simultaneously illuminating the photochromic plate by a reference beam from a coherent source of light of a frequency different from that employed in the production of said first diffraction pattern and lying substantially entirely within the visible spectrum, and superimposing a second diffraction pattern employing light from said coherent source of visible light on said first diffraction pattern on said photochromic plate, whereby the reference beam illumination and said diffraction pattern form a photochromically generated hologram to modify said first diffraction pattern.
Claim 3
Independent Claim
152 words
A method of processing optical information, using a hologram as a spatial filter, comprising producing a first diffraction pattern on a photochromic plate by illumination of an object disposed in a beam of coherent light which is uncollimated, said photochromic plAte incorporating material that exhibits normally unpopulated triplet states of molecular energy population of which can be induced by photons of visible light energy, simultaneously illuminating the photochromic plate by a reference beam from a coherent source of light lying substantially entirely within the visible spectrum and containing said photons for inducing population of the triplet states of said photochromic plate material with normally unpopulated triplet states, and superimposing a second diffraction pattern employing light from said coherent source of visible light on said first diffraction pattern on said photochromic plate, whereby the reference beam illumination and said second diffraction pattern form a photochromically generated hologram to modify said first diffraction pattern.
Claim 4
Independent Claim
152 words
A method of processing optical information, using a hologram as a spatial filter, comprising producing a first diffraction pattern on a photochromic plate by illumination of an object disposed in a beam of coherent light which is uncollimated, said photochromic plAte incorporating material that exhibits normally unpopulated triplet states of molecular energy population of which can be induced by photons of visible light energy, simultaneously illuminating the photochromic plate by a reference beam from a coherent source of light lying substantially entirely within the visible spectrum and containing said photons for inducing population of the triplet states of said photochromic plate material with normally unpopulated triplet states, and superimposing a second diffraction pattern employing light from said coherent source of visible light on said first diffraction pattern on said photochromic plate, whereby the reference beam illumination and said second diffraction pattern form a photochromically generated hologram to modify said first diffraction pattern.
References Cited (Backward Citations)
US3085469A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-02-07 | 1975-08-09 | 1976-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-07 | 1979-08-09 | 1980-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-07 | 1983-08-09 | 1984-02-08 | $7700.00 | Window Closed / Lapsed |