US3742382A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for stabilizing a laser to a gas absorption line
Assignee: AT&T Inc
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Filing: 1972-04-03
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Granted: 1973-06-26
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Expires: 1992-04-03
Abstract
Abstract There is disclosed a frequency-stabilized laser in which a first component of the output beam is passed through a gaseous frequency standard cell in a first direction and then detected while a second component of the beam is passed through the cell in a second direction slightly less than 180* from the first direction so as to avoid subsequent interaction with the apparatus. The detected signal as a function of frequency has a narrow peak centered on the absorption line of the gas. The width of this peak is the homogeneous linewidth of the absorbing gas, which is typically much narrower than the Doppler-broadened absorption line. The detected signal is applied through a feedback loop to control the tuning of the laser resonator.
Inventors
- 👤 P Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:41
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/10; H01S3/13; H01S3/139; H01S3/1396
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
242 words
Apparatus for frequency stabilizing a laser, comprising a laser including a tunable resonator that permits the emission of an output beam of coherent radiation therefrom, a frequency standard cell containing a gaseous medium having an absorption within the output bandwidth of said laser, means including a beam splitter for passing a first portion of said beam through said cell in a first direction, means for passing a second portion of said beam through said cell in a second direction slightly less than 180 degrees from said first direction, the means for passing the second portion of the beam through the cell including means for chopping said second portion, means for detecting the first portion of the beam after passage through said cell, and means responsive to said detecting means for tuning said resonator to stabilize a parameter of the detected first portion, the means for tuning the resonator comprising means for generating first and second refeRence signals, the first reference signal being chopped at the chopping rate of said second portion of said beam and having a fixed phase relative thereto, phase sensitive means for detecting a difference between the first reference signal and the detected first portion, means for comparing a signal responsive to said difference to the second reference signal, and means responsive to said comparing means for applying a correction signal to tune the resonator to tend to make the compared difference signal equal to said second reference signal.
Claim 2
Dependent Claim
242 words
Apparatus for frequency stabilizing a laser, comprising a laser including a tunable resonator that permits the emission of an output beam of coherent radiation therefrom, a frequency standard cell containing a gaseous medium having an absorption within the output bandwidth of said laser, means including a beam splitter for passing a first portion of said beam through said cell in a first direction, means for passing a second portion of said beam through said cell in a second direction slightly less than 180 degrees from said first direction, the means for passing the second portion of the beam through the cell including means for chopping said second portion, means for detecting the first portion of the beam after passage through said cell, and means responsive to said detecting means for tuning said resonator to stabilize a parameter of the detected first portion, the means for tuning the resonator comprising means for generating first and second refeRence signals, the first reference signal being chopped at the chopping rate of said second portion of said beam and having a fixed phase relative thereto, phase sensitive means for detecting a difference between the first reference signal and the detected first portion, means for comparing a signal responsive to said difference to the second reference signal, and means responsive to said comparing means for applying a correction signal to tune the resonator to tend to make the compared difference signal equal to said second reference signal.
Claim 3
Dependent Claim
68 words
Apparatus according to claim 1 in which the cell comprises end windows transparent at the oscillation frequency of the laser and in which the means for passing the second portion of the beam through the cell includes a plurality of reflectors disposed to avoid intercepting the first portion of the beam while directing said second portion through the end windows of the cell without intercepting the beam splitter.
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) | 1976-06-25 | 1976-12-25 | 1977-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-25 | 1980-12-25 | 1981-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-25 | 1984-12-25 | 1985-06-26 | $7700.00 | Window Closed / Lapsed |