Patent US4068190A successfully refreshed from Google Patents.
US4068190A
Expired / Lapsed
US
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Laser system having frequency doubling
Assignee: United States Department of the Navy
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Filing: 1976-02-09
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Granted: 1978-01-10
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Expires: 1996-02-09
Abstract
Abstract A laser system for ocean radar applications having a resonant chamber for producing a pair of homogenized, singularly polarized output beams having identical pulse widths and energies. A quarter wave plate is inserted within the optical path of the resonant chamber and rotates the birefringence effects of a laser crystal positioned within the chamber to generate a pair of homogenized, orthogonally polarized beams. A selected one of the orthogonally polarized beams is transmitted through a half wave plate and joins with the remaining beam for passage through a telescope assembly to minimize the cross-sectional area of the beams. A doubler crystal receives the telescoped beams and doubles the frequency thereof to form the pair of homogenized output beams having light energy in the green spectrum.
Inventors
- 👤 Gerald D. Ferguson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 17:54
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/10; H01S3/11; H01S3/1123; H01S3/115; G; G02; G02F; G02F1/00; G02F1/35; G02F1/37
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
254 words
A laser system, comprising, in combination: first and second mirrors spatially positioned to form an optically resonant chamber, said first and second mirrors being partially and fully reflective, respectively; solid-state laser means positioned in said chamber to radiate laser energy along a first optical axis extending through said mirrors; polarizer means positioned along the first axis for directing the radiation of one polarity along the first axis to said first mirror and radiation of another polarity along a second optical axis extending through said first mirror and parallel to the first axis, for maintaining radiation of the one polarity returning along the first axis on the first axis and for directing the radiation of the other polarity out of said chamber, and for directing the radiation of the other polarity returning along the second axis into the first axis and for directing the radiation of the one polarity along the second axis out of said chamber; a Pockels cell positioned along the first and second axes for changing the respective polarities of the returning radiation; a quarter-wave plate positioned on the first axis for changing the polarities of the radiation returning from said second mirror; a half-wave plate positioned on the second axis for changing the radiation passed through said first mirror from the other to the one polarity; and frequency doubling crystal positioned on said first and second axes to receive the radiation of the one polarity from said first mirror and from said half-wave plate for doubling the frequency of the radiation.
Claim 2
Dependent Claim
254 words
A laser system, comprising, in combination: first and second mirrors spatially positioned to form an optically resonant chamber, said first and second mirrors being partially and fully reflective, respectively; solid-state laser means positioned in said chamber to radiate laser energy along a first optical axis extending through said mirrors; polarizer means positioned along the first axis for directing the radiation of one polarity along the first axis to said first mirror and radiation of another polarity along a second optical axis extending through said first mirror and parallel to the first axis, for maintaining radiation of the one polarity returning along the first axis on the first axis and for directing the radiation of the other polarity out of said chamber, and for directing the radiation of the other polarity returning along the second axis into the first axis and for directing the radiation of the one polarity along the second axis out of said chamber; a Pockels cell positioned along the first and second axes for changing the respective polarities of the returning radiation; a quarter-wave plate positioned on the first axis for changing the polarities of the radiation returning from said second mirror; a half-wave plate positioned on the second axis for changing the radiation passed through said first mirror from the other to the one polarity; and frequency doubling crystal positioned on said first and second axes to receive the radiation of the one polarity from said first mirror and from said half-wave plate for doubling the frequency of the radiation.
Claim 3
Dependent Claim
16 words
A laser system according to claim 1 wherein said one and other polarities are mutually orthogonal.
Claim 4
Dependent Claim
16 words
A laser system according to claim 2 wherein said laser means is a neodymium-doped YAG crystal.
Claim 5
Dependent Claim
38 words
A laser system according to claim 3 further comprising: optical means positioned on the first and second axes between said half-wave plate and said doubling means for decreasing the cross-sectional area of the radiation to said doubling means.
References Cited (Backward Citations)
US3529885A
Cited
US3564454A
Cited
US3798571A
Cited
US3670258A
Cited
US3684350A
Cited
US3740663A
Cited
DE2220173A1
Cited
US3928818A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-01-09 | 1981-07-11 | 1982-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-09 | 1985-07-11 | 1986-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-09 | 1989-07-11 | 1990-01-10 | $7700.00 | Window Closed / Lapsed |