US3596201A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Frequency stabilized laser
Assignee: Raytheon Co
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Filing: 1970-06-08
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Granted: 1971-07-27
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Expires: 1990-06-08
Abstract
Abstract A frequency stabilized laser is disclosed in which active laser material exhibiting Zeeman effects is disposed in a resonant laser cavity to which an axial magnetic field is applied for producing Zeeman-splitting, and in which a feedback error signal is applied to adjust the frequency of laser oscillation. Optical means, including quarter-wave plates, are disposed in the laser cavity for insuring that the laser energy propagating in the laser material in a first axial direction is polarized in a first circular polarization sense only, as measured with respect to the direction of the applied magnetic field, and for insuring that the laser energy propagating in the laser material in the opposite axial direction is polarized in the opposite circular polarization sense only, as measured with respect to the direction of the magnetic field.
Inventors
- 👤 Arthur N Chester
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 03:33
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/10; H01S3/13; H01S3/139; H01S3/1396
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
243 words
A frequency stabilized laser comprising: a laser medium capable of exhibiting Zeeman effects; pump means coupled to said laser medium for exciting said medium so that it produces and emits from opposite ends thereof respective first and second beams of laser energy propagating in opposite longitudinal directions; first and second reflectors spaced from the respective ends of said laser medium and disposed in the respective paths of said first and second laser beams for reflecting most of the laser energy in said beams back into said medium; transducer means coupled to one of said reflectors for adjusting the frequency of laser oscillation; Zeeman-splitting means disposed adjacent said laser medium for producing a longitudinal magnetic field of an essentially constant magnitude; a first quarter-wave plate disposed in the path of said first laser beam between said laser medium and said first reflector; a plane polarizer element disposed in the path of said first laser beam between said first quarter-wave plate and said first reflector; a second quarter-wave plate disposed in the path of said second laser beam between said laser medium and said second reflector; and comparison means including a first photodetector coupled to said first laser beam, a second photodetector coupled to said photodetectors and to said transducer means for comparing the intensity of said first and second laser beams and for providing an error signal of a magnitude and sense to adjust the frequency of laser oscillation to minimize said error signal.
Claim 2
Dependent Claim
253 words
A frequency stabilized laser comprising: a laser medium capable of exhibiting Zeeman effects; pump means coupled to said laser medium for exciting said medium so that it produces and emits from opposite ends thereof respective first and second beams of laser energy propagating in opposite longitudinal directions; first and second reflectors spaced from the respective ends of said laser medium and disposed in the respective paths of said first and second laser beams for reflecting most of the laser energy in said beams back into said medium; transducer means coupled to one of said reflectors for adjusting the frequency of laser oscillation; Zeeman-splitting means disposed adjacent said laser medium for producing a longitudinal magnetic field of an essentially constant magnitude; a first quarter-wave plate disposed in the path of said first laser beam between said laser medIum and said first reflector; a Brewster angle window disposed in the path of said first laser beam between said first quarter-wave plate and said first reflector; a second quarter-wave plate disposed in the path of said second laser beam between said laser medium and said second reflector; and comparison means including a first photodetector coupled to said first laser beam, a second photodetector coupled to said second laser beam, and a comparator circuit coupled to said photodetectors and to said transducer means for comparing the intensity of said first and second laser beams and for providing an error signal of a magnitude and sense to adjust the frequency of laser oscillation to minimize said error signal.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-07-26 | 1975-01-25 | 1975-07-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-26 | 1979-01-25 | 1979-07-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-26 | 1983-01-25 | 1983-07-27 | $7700.00 | Window Closed / Lapsed |