Patent US3628173A successfully refreshed from Google Patents.
US3628173A
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Laser mode selection and stabilization apparatus employing a birefringement etalon
Assignee: AT&T Inc
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Filing: 1969-04-28
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Granted: 1971-12-14
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Expires: 1989-04-28
Abstract
Abstract There is disclosed a stabilized single-frequency arrangement for a broadband laser, such as a neodymium ion laser, in which a resonant etalon including birefringent material is disposed in the resonator in the path of the radiation and is tilted to select only one axial mode of oscillation in each of two orthogonal polarizations. In one specific embodiment, the resonator is tuned for maximum intensity of the mode of one polarization in response to a nearly linear intensity-frequency discriminant derived from the mode of the other polarization, which is provided with an operating point on a side of a transmission curve of the etalon.
Inventors
- 👤 Hans G Danielmeyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:21
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/05; H01S3/08; H01S3/08018; H01S3/08022; H01S3/08031; H01S3/08036; H01S3/10; H01S3/13; H01S3/139; H01S3/1398
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
179 words
Apparatus for generating frequency-controlled coherent electromagnetic radiation comprising: a laser having an optical resonator and an active medium capable of the stimulated emission of radiation in a plurality of axial modes in each of two orthogonal polarizations, a resonant etalon including birefringent material disposed in said resonator in the path of said radiation and tilted to select only one axial mode of oscillation in each of said orthogonal polarizations, feedback means including means for separating the selected modes of orthogonal polarization, means for detecting the intensity of one of said modes on one polarization and comparing it to a reference level, and means responsive to the detecting and comparing means for changing the optical pathlength of the optical resonator to reduce the deviation of the detected intensity from the reference level, and means for tuning the etalon to move the sets of modes in frequency for the two orthogonal polarizations with respect to the gain curve and with respect to each other to obtain a desired operating point and a desired intensity versus frequency discriminant for the feedback means.
Claim 2
Dependent Claim
180 words
Apparatus for generating frequency-controlled coherent electromagnetic radiation comprising a laser having an optical resonator and an active medium capable of the stimulated emission of radiation in a plurality of axial modes in each of two orthogonal polarizations, a resonant etalon including birefringent material disposed in said resonator in the path of said radiation and tilted to select only one axial mode of oscillation in each of said orthogonal polarizations, feedback means including means for separating the selected modes of orthogonal polarizations, means for detecting the intensity of one of said modes on one polarization and comparing it to a reference level, and means responsive to the detecting and comparing means for changing the optical pathlength of the optical resonator to reduce the deviation of the detected intensity from the reference level, and means for controlling the temperature of the etalon to provide that the detected mode has an operating point on a nearly linear side region of a transmission-versus-frequency curve of said etalon, whereby a nearly linear intensity-versus-frequency discriminant is obtained at the output of the detecting and comparing means.
Claim 3
Dependent Claim
48 words
Apparatus according to claim 1 in which said means for tuning the etalon comprises means for controlling the temperature of the etalon, whereby the optical path lengths and consequently the sets of modes for each of said orthogonal polarizations in the etalon change with temperature at different rates.
Claim 4
Dependent Claim
48 words
Apparatus according to claim 2 in which said means for tuning the etalon comprises means for controlling the temperature of the etalon, whereby the optical path lengths and consequently the sets of modes for each of said orthogonal polarizations in the etalon change with temperature at different rates.
References Cited (Backward Citations)
US3436678A
Cited
US3482099A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-12-13 | 1975-06-14 | 1975-12-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-13 | 1979-06-14 | 1979-12-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-13 | 1983-06-14 | 1983-12-14 | $7700.00 | Window Closed / Lapsed |