US4118675A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Laser tuning with an acousto-optic lens
Assignee: United States Department of the Navy
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Filing: 1977-03-31
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Granted: 1978-10-03
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Expires: 1997-03-31
Abstract
Abstract A pulsed laser having a laser gain medium of broadband output is tuned to essentially monochromatic output. An acousto-optic cell is driven with an acoustic wave which varies linearly in frequency, causing the laser beam to be resolved into a number of essentially monochromatic focal points. The focused beam of the desired wavelength is reflected to the output through one or more apertures which block out the unwanted wavelengths.
Inventors
- 👤 John P. Rahn
- 👤 Marion L. Scott
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 12:23
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/10; H01S3/106; H01S3/1068
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
116 words
A method for tuning a pulsed laser beam in a laser having a laser gain medium between an output element and a back reflector comprising the steps of: passing said laser beam through substantially the entire length of an acousto-optic cell disposed between said laser medium and said back reflector; focusing said laser beam by propagating a chirped acoustic pulse through said acoustic-optic cell; providing spectral resolution of said laser beam into wavelength components by propagating a chirped acoustic pulse through said acousto-optic cell; blocking all but one of said wavelength components with an aperture; and reflecting one wavelength component with said back reflector through the acousto-optic cell, the laser gain medium and the output element.
Claim 2
Independent Claim
116 words
A method for tuning a pulsed laser beam in a laser having a laser gain medium between an output element and a back reflector comprising the steps of: passing said laser beam through substantially the entire length of an acousto-optic cell disposed between said laser medium and said back reflector; focusing said laser beam by propagating a chirped acoustic pulse through said acoustic-optic cell; providing spectral resolution of said laser beam into wavelength components by propagating a chirped acoustic pulse through said acousto-optic cell; blocking all but one of said wavelength components with an aperture; and reflecting one wavelength component with said back reflector through the acousto-optic cell, the laser gain medium and the output element.
Claim 3
Dependent Claim
22 words
The method of claim 1 further including the step of: making said laser beam divergent before it passes through said acousto-optic cell.
Claim 4
Dependent Claim
151 words
In a pulsed laser having an optical cavity wherein a laser beam passes along the optical path in said cavity, a tuning device comprising an acousto-optic cell along the optical path, in the optical cavity; a beam expander along the optical cavity for enlarging said laser beam in order that it passes through substantially the entire length of said cell. means connected to the acousto-optic cell for impressing a chirped acoustic wave on the acousto-optic cell whereby laser light passing through the cell is focused into a number of wavelength components; a one hundred percent back reflector at one end of the optical cavity and at a fixed point along the optical path for reflecting at least one wavelength component back through the optical cavity; and means at a fixed point along the optical path in the optical cavity for blocking all but one wavelength component from exiting the laser cavity.
Claim 5
Dependent Claim
151 words
In a pulsed laser having an optical cavity wherein a laser beam passes along the optical path in said cavity, a tuning device comprising an acousto-optic cell along the optical path, in the optical cavity; a beam expander along the optical cavity for enlarging said laser beam in order that it passes through substantially the entire length of said cell. means connected to the acousto-optic cell for impressing a chirped acoustic wave on the acousto-optic cell whereby laser light passing through the cell is focused into a number of wavelength components; a one hundred percent back reflector at one end of the optical cavity and at a fixed point along the optical path for reflecting at least one wavelength component back through the optical cavity; and means at a fixed point along the optical path in the optical cavity for blocking all but one wavelength component from exiting the laser cavity.
Claim 6
Dependent Claim
19 words
The device of claim 3 wherein the beam expander is a pair of lenses which collimate the laser beam.
Claim 7
Dependent Claim
16 words
The device of claim 3 wherein said one hundred percent back reflector is a concave mirror.
Claim 8
Dependent Claim
30 words
The device of claim 5 wherein said means for blocking all but one wavelength component is an aperture along the optical path between the acousto-optic cell and the concave mirror.
Claim 9
Dependent Claim
13 words
The device of claim 3 wherein said beam expander is a divergent lens.
Claim 10
Dependent Claim
18 words
The device of claim 3 wherein said one hundred percent back reflector is affixed to the acousto-optic cell.
Claim 11
Dependent Claim
29 words
The device of claim 8 wherein said one hundred percent back reflector and said acousto-optic cell are at the Bragg angle to the beam diverging to the acousto-optic cell.
Claim 12
Dependent Claim
36 words
The device of claim 3 wherein said means for blocking all but one wavelength component is at least one aperture at a fixed position along the optical path between the output mirror and the beam expander.
References Cited (Backward Citations)
US3483387A
Cited
US3735278A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-10-02 | 1982-04-03 | 1982-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-10-02 | 1986-04-03 | 1986-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-10-02 | 1990-04-03 | 1990-10-03 | $7700.00 | Window Closed / Lapsed |