US3723004A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Laser velocimeter employing dual scatter detection
Assignee: United States Department of the Air Force
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Filing: 1971-05-18
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Granted: 1973-03-27
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Expires: 1991-05-18
Abstract
Abstract A doppler shift laser velocimeter is disclosed that employs a self-aligning optical system capable of determining one or more velocity components of a moving substance. The beam from a plane polarized laser source is automatically split into two or more plane polarized parallel path beams by one or more parallel surface glass blocks. Certain ones of these beams are then polarization plane rotated and all beams are directed onto a focusing element which automatically focuses them to a common point P in space. Velocity components of a moving substance are detected by photo-detecting radiations simultaneously scattered from the moving substance and from the polarization rotated illuminating beams. Means are connected to the outputs of the photodetectors for determining the frequencies of the electrical signals. These frequencies are proportioned to specific velocity components of the moving substance.
Inventors
- 👤 D Brayton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 05:30
CPC Classifications
G; G01; G01P; G01P3/00; G01P3/36; G01P3/366
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
166 words
A laser doppler shift two velocity component measuring system comprising, means for providing a plane polarized collimated input light beam, means for splitting said input light beam into first, second and third plane polarized parallel light beams having an output beam pattern that forms a right triangle, polarization rotating means in intercepting relationship with said first and said third light beams, means for causing the first and third polarization rotated light beams and said second light beam to converge and focus at a common point, a member having a pinhole aperture therein, means for collecting light scattered in the vicinity of said common point and focusing it on said aperture, polarization separation means positioned to receive light transmitted through said aperture, a collimating lens positioned between said aperture and said polarization separation means, a first photodetector means positioned to receive light of one polarization from said polarization separation means, and a second photodetector means positioned to receive light of another polarization from said polarization separation means.
Claim 2
Dependent Claim
166 words
A laser doppler shift two velocity component measuring system comprising, means for providing a plane polarized collimated input light beam, means for splitting said input light beam into first, second and third plane polarized parallel light beams having an output beam pattern that forms a right triangle, polarization rotating means in intercepting relationship with said first and said third light beams, means for causing the first and third polarization rotated light beams and said second light beam to converge and focus at a common point, a member having a pinhole aperture therein, means for collecting light scattered in the vicinity of said common point and focusing it on said aperture, polarization separation means positioned to receive light transmitted through said aperture, a collimating lens positioned between said aperture and said polarization separation means, a first photodetector means positioned to receive light of one polarization from said polarization separation means, and a second photodetector means positioned to receive light of another polarization from said polarization separation means.
Claim 3
Dependent Claim
63 words
A laser doppler shift two velocity component measuring system as defined in claim 1 wherein said means for collecting light scattered in the vicinity of said common point and focusing it on said aperture includes a partial mirror disposed between said polarization rotating means and said means for causing said first, second and third beams to converge and focus at a common point.
Claim 4
Dependent Claim
62 words
A laser doppler shift two velocity component measuring system as defined in claim 2 wherein said means for splitting said input light beam into first, second and third plane polarized parallel light beams comprises parallel surface glass blocks having spatial relationships and orientations adapted to generate at least three parallel output beams having an output beam pattern that forms a right triangle.
References Cited (Backward Citations)
US3548655A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-03-26 | 1976-09-25 | 1977-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-26 | 1980-09-25 | 1981-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-26 | 1984-09-25 | 1985-03-27 | $7700.00 | Window Closed / Lapsed |