US5274494A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Speckle suppression illuminator
Assignee: Raytheon Co
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Filing: 1993-01-11
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Granted: 1993-12-28
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Expires: 2013-01-11
Abstract
Abstract Disclosed is a method and apparatus for reducing or eliminating the speckle intensity distribution of an imaging and/or tracking system The benefits of utilizing a highly coherent source (12) as an imaging and tracking system are well known. However, such a coherent source (12) provides a speckle intensity distribution which reduces the effective resolution capability of the imaging system. This invention takes a coherent beam of light (14) and impinges it into a Raman cell (16) to obtain a broad spectral bandwidth beam of light having additional side wavelengths other than the original wavelength. In addition, this invention provides a means to improve the beam quality of all of the Raman lines. Therefore, a composite beam having broad spectral bandwidth composed of individual spectral lines having good beam quality is generated. As a result of the broad spectral bandwidth, images formed from targets illuminated by such a composite beam are substantially free of speckle intensity variations.
Inventors
- 👤 Gerard L. Rafanelli
- 👤 Claudio G. Parazzoli
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 13:47
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/48; H; H01; H01S; H01S3/00; H01S3/005
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
88 words
A system for actively illuminating or tracking a target at a distance in a day or night environment, said system including: a source of coherent light at a first wavelength; and a first RAMAN cell having a gas for receiving said coherent light and for emitting light at said first wavelength and a plurality of side wavelengths to provide a beam having spatial coherence and temporal incoherence sufficient to illuminate or track said target in a day or night environment at said distance with substantial elimination of speckle.
Claim 2
Independent Claim
88 words
A system for actively illuminating or tracking a target at a distance in a day or night environment, said system including: a source of coherent light at a first wavelength; and a first RAMAN cell having a gas for receiving said coherent light and for emitting light at said first wavelength and a plurality of side wavelengths to provide a beam having spatial coherence and temporal incoherence sufficient to illuminate or track said target in a day or night environment at said distance with substantial elimination of speckle.
Claim 3
Dependent Claim
27 words
The system of claim 1 further including: a beam clean up device for receiving said plurality of said wavelengths to alter the wavefronts of said side wavelengths.
Claim 4
Dependent Claim
32 words
The system of claim 1 further including: a second RAMAN cell for receiving said first and said plurality of side wavelengths and for providing said beam to illuminate to track said target.
Claim 5
Independent Claim
149 words
A system for actively illuminating or tracking a target at a distance in a day or night environment comprising: a source of coherent light at a first wavelength; a first RAMAN cell having a gas for receiving said coherent light and for emitting light at said first wavelength and a plurality of side wavelengths means for splitting said first wavelength from said plurality of side wavelengths; a beam clean-up device for receiving said plurality of side wavelengths to alter the wavefronts to provide clean-up side wavelengths; means for recombining said first wavelength and said cleaned-up side wavelengths; and a second RAMAN cell having a gas for receiving said first wavelength and said plurality of cleaned-up side wavelengths and for providing a beam having spatial coherence and temporal incoherence sufficient to illuminate or track said target in a day or night environment at said distance with substantial elimination of speckle.
Claim 6
Independent Claim
149 words
A system for actively illuminating or tracking a target at a distance in a day or night environment comprising: a source of coherent light at a first wavelength; a first RAMAN cell having a gas for receiving said coherent light and for emitting light at said first wavelength and a plurality of side wavelengths means for splitting said first wavelength from said plurality of side wavelengths; a beam clean-up device for receiving said plurality of side wavelengths to alter the wavefronts to provide clean-up side wavelengths; means for recombining said first wavelength and said cleaned-up side wavelengths; and a second RAMAN cell having a gas for receiving said first wavelength and said plurality of cleaned-up side wavelengths and for providing a beam having spatial coherence and temporal incoherence sufficient to illuminate or track said target in a day or night environment at said distance with substantial elimination of speckle.
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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) | 1996-12-27 | 1997-06-28 | 1997-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-12-27 | 2001-06-28 | 2001-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-12-27 | 2005-06-28 | 2005-12-28 | $7700.00 | Window Closed / Lapsed |