US3730625A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Laser velocimeter employing reference beam detection
Assignee: United States Department of the Air Force
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Filing: 1971-02-26
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Granted: 1973-05-01
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Expires: 1991-02-26
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 beams by one or more parallel surface glass blocks. These beams are then directed onto a focusing element which automatically focuses them to a common point P in space. One or more velocity components of a moving substance are detected by placing photodetectors in the paths of one or more of the beams after they have traversed through or reflected from the moving substance near the common point P. Means are connected to the outputs of the photodetectors for determining the frequencies of the electrical signals. These frequencies are proportional to the specific velocity components of the moving substance.
Inventors
- 👤 D Brayton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:52
CPC Classifications
G; G01; G01S; G01S17/00; G01S17/02; G01S17/50; G01P; G01P3/00; G01P3/36; G01P3/366
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
164 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 and second plane polarized parallel light beams, means for limiting the intensity of said first plane polarized light beam, means for splitting said intensity limited light beam into first and second plane polarized parallel reference light beams, said reference light beam being parallel to and in orthogonal relationship with said second plane polarized light beam, means for limiting the intensity of said first and second reference light beam, means for causing said first and second intensity limited reference beams and said second plane polarized light beam to converge and focus at a common point, a first photodetector means positioned proximate to and beyond said common point and oriented to receive said first reference beam, and a second photodetector means positioned proximate to and beyond said common point and oriented to receive said second reference beam.
Claim 2
Dependent Claim
164 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 and second plane polarized parallel light beams, means for limiting the intensity of said first plane polarized light beam, means for splitting said intensity limited light beam into first and second plane polarized parallel reference light beams, said reference light beam being parallel to and in orthogonal relationship with said second plane polarized light beam, means for limiting the intensity of said first and second reference light beam, means for causing said first and second intensity limited reference beams and said second plane polarized light beam to converge and focus at a common point, a first photodetector means positioned proximate to and beyond said common point and oriented to receive said first reference beam, and a second photodetector means positioned proximate to and beyond said common point and oriented to receive said second reference beam.
Claim 3
Dependent Claim
28 words
A laser doppler shift two velocity component measuring system as defined in claim 1 including a positive lens positioned between said common point and each said photodetector means.
Claim 4
Dependent Claim
81 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 and second plane polarized parallel light beams and said means for splitting said intensity limited light beam into first and second plane polarized parallel reference light beams comprise parallel surface glass blocks having spatial relationships and orientation adapted to generate at least three parallel output beams having an output beam pattern that forms a right triangle.
References Cited (Backward Citations)
GB342219A
Cited
US3548655A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-04-30 | 1976-10-30 | 1977-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-30 | 1980-10-30 | 1981-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-30 | 1984-10-30 | 1985-05-01 | $7700.00 | Window Closed / Lapsed |