Patent US3662279A successfully refreshed from Google Patents.
US3662279A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for controlling the frequency of a laser beam
Assignee: Sandstroem & Others
•
Filing: 1970-10-20
•
Granted: 1972-05-09
•
Expires: 1990-10-20
Abstract
Abstract A system for stabilizing the frequency of a laser having the resonator reflectors mounted on the ends of a gas discharge tube by controlling the temperature of the tube in response to an optical output signal from the laser.
Inventors
- 👤 Unto Sandstrom
- 👤 Nils Abramson
- 👤 Ulf Sjolin
- 👤 Henrick Murray
- 👤 Bertil Colding
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 08:17
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/10; H01S3/13; H01S3/139; H01S3/1396
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
200 words
A laser device for controlling the frequency of the radiation emitted from the laser, each of the oscillation modes maintained in the laser having a polarization direction which is perpendicular to the polarization direction of adjacent oscillation modes, in addition to which part of the radiation emitted from the laser is supplied to a detector, the output signal of which is fed to means for controlling the temperature of the laser tube which controls the adjustment of the optical distance between the laser reflectors which are mounted on the ends of the laser tube, characterized in that the laser has such a limited distance between the reflectors that substantially only two to five oscillation modes are amplified by the laser, and that the detector and sensing means combined with it selectively sense the radiation in one of the polarization directions, in addition to which a signal produced at this selective sensing means is supplied to the temperature controlling means, which adjust the optical distance between the laser reflectors so that the frequency of oscillation modes corresponding to the sensed polarization direction is controlled relative to the maximum point of the spectral line of the laser widened by the Doppler effect.
Claim 2
Dependent Claim
200 words
A laser device for controlling the frequency of the radiation emitted from the laser, each of the oscillation modes maintained in the laser having a polarization direction which is perpendicular to the polarization direction of adjacent oscillation modes, in addition to which part of the radiation emitted from the laser is supplied to a detector, the output signal of which is fed to means for controlling the temperature of the laser tube which controls the adjustment of the optical distance between the laser reflectors which are mounted on the ends of the laser tube, characterized in that the laser has such a limited distance between the reflectors that substantially only two to five oscillation modes are amplified by the laser, and that the detector and sensing means combined with it selectively sense the radiation in one of the polarization directions, in addition to which a signal produced at this selective sensing means is supplied to the temperature controlling means, which adjust the optical distance between the laser reflectors so that the frequency of oscillation modes corresponding to the sensed polarization direction is controlled relative to the maximum point of the spectral line of the laser widened by the Doppler effect.
Claim 3
Dependent Claim
15 words
Device according to claim 1, characterized in that the laser used is a gas laser.
Claim 4
Dependent Claim
38 words
Device according to claim 2, characterized in that the laser is designed so that each one of the laser reflectors is rigidly connected with each one of the end parts of the gas discharge tube of the laser.
Claim 5
Dependent Claim
35 words
Device according to claim 2, characterized in that said temperature controlling means influence the temperature of the tube used in the gas laser by controlling the temperature in at least one part of said tube.
Claim 6
Dependent Claim
45 words
Device according to claim 4, characterized in that the laser tube is provided with a metallization, to which an electrical current heating the laser tube is supplied by connectors, the size of said current being controlled by the output signal from the selective sensing means.
Claim 7
Dependent Claim
32 words
Device according to claim 4, characterized in that said temperature controlling means produce a temperature controlling air flow, which is directed to the laser tube and the effect of which is controllable.
Claim 8
Dependent Claim
33 words
Device according to claiM 6, characterized in that the output signal from the selective sensing means is arranged to adjust the time during which the air flow is led towards the laser tube.
Claim 9
Dependent Claim
39 words
Device according to claim 1, characterized in that in the beam path between the laser and the detector, means are included, which alternately transmit the two polarization directions for achieving a periodical variation of the radiations reaching the detector.
Claim 10
Dependent Claim
22 words
Device according to claim 8, characterized in that said means for alternately transmitting the two polarization directions comprise a rotating polarizing filter.
Claim 11
Dependent Claim
40 words
Device according to claim 9, characterized in that the filter is connected to means for producing an electrical voltage representing the instantaneous position of the filter relative to the polarization directions of the radiation from the laser towards the detector.
Claim 12
Dependent Claim
60 words
Device according to claim 10, characterized in that this voltage together with the output voltage from the detector is supplied to an amplifier in such manner that only part of the output voltage from the detector and corresponding to one of the polarization directions is amplified and is supplied to the means for adjusting the optical distance between the reflectors.
Claim 13
Dependent Claim
40 words
Device according to claim 11, characterized in that the output voltage from the amplifier is supplied to a relay means controlling the current supply to a motor, which drives a ventilator for sending an air flow to the laser tube.
Claim 14
Dependent Claim
66 words
Device according to claim 1, characterized in that the detector receives radiation from the laser tube through the least transparent reflector in the laser, a second, adjustable, polarizing filter being located outside the other reflector, whose polarization direction can be brought to agree with the polarization direction of the oscillation mode, which via the detector and means combined with it controls the distance between the reflectors.
Claim 15
Dependent Claim
57 words
Device according to claim 1, characterized in that the radiation from the laser is divided into two components having perpendicular polarization directions each one being supplied to one of two photo resistors included in a bridge connection, the output voltage from the bridge being supplied to said means for controlling the optical distance between the laser reflectors.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-09 | 1975-11-08 | 1976-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-09 | 1979-11-08 | 1980-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-09 | 1983-11-08 | 1984-05-09 | $7700.00 | Window Closed / Lapsed |