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Patent US4575245A successfully refreshed from Google Patents.
US4575245A
Expired / Lapsed
US
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Interferometric optical devices with phase conjugating mirrors in particular for laser gyrometers
Assignee: Centre National de la Recherche Scientifique
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Filing: 1982-04-08
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Granted: 1986-03-11
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Expires: 2002-04-08
Abstract
Abstract A laser radiation arrives at a separating plate, after which a first part of the radiation is applied to a fibre optic wound with N turns to end at a phase conjugating mirror which returns the radiation into the same fibre optic. The other part of the radiation, reflected by the plate, travels in a fibre optic defining another optical path, very close to the first, and wound in the opposite direction for N turns, terminating at the same phase conjugating mirror or at another mirror of the same type, which returns the incident wave through the same fibre optic. The state of interference, detected at the separating plate by a detector, represents any rotation of the gyrometer. The phase conjugating mirror or mirrors is or are advantageously defined by optically non-linear media energized by two plane pump waves and travelling in opposite directions but on a colinear basis.
Inventors
- 👤 Christian J. R. Borde
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 12:09
CPC Classifications
G; G01; G01C; G01C19/00; G01C19/58; G01C19/64; G01C19/72
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
134 words
An interferometric optical device comprising: an input for receiving laser radiation; means positioned to receive said laser radiation for separating said laser radiation into first and second split beams propagating respectively along first and second beam paths; first mirror means positioned in said first beam path for returning a first reflected beam which is a phase conjugate of said first split beam back along said first beam path; second mirror means positioned in said second beam path for returning a second reflected beam which is a phase conjugate of said second split beam back along said second beam path; and means positioned to receive said first and second reflected beams for comparing said first and second reflected beams through their mutual interference, and thus for detecting an optical non-reciprocity in said first beam path.
Claim 2
Dependent Claim
134 words
An interferometric optical device comprising: an input for receiving laser radiation; means positioned to receive said laser radiation for separating said laser radiation into first and second split beams propagating respectively along first and second beam paths; first mirror means positioned in said first beam path for returning a first reflected beam which is a phase conjugate of said first split beam back along said first beam path; second mirror means positioned in said second beam path for returning a second reflected beam which is a phase conjugate of said second split beam back along said second beam path; and means positioned to receive said first and second reflected beams for comparing said first and second reflected beams through their mutual interference, and thus for detecting an optical non-reciprocity in said first beam path.
Claim 3
Dependent Claim
18 words
An interferometric optical device according to claim 1, wherein the first mirror means comprises an optically non-linear medium.
Claim 4
Dependent Claim
26 words
An interferometric optical device according to claim 2, wherein there are provided means for applying two pump waves of respective opposite directions to the non-linear medium.
Claim 5
Dependent Claim
25 words
An interferometric optical device according to claim 3, wherein said pump wave applying means is adapted to apply two pump waves of the same frequency.
Claim 6
Dependent Claim
29 words
An interferometric optical device according to claim 4, wherein the pump wave applying means are adapted to produce the pump waves from a part of the input laser radiation.
Claim 7
Dependent Claim
61 words
An interferometric optical device according to claim 1, wherein the separating means is positioned to receive said first and second reflected beams, and wherein the comparing means includes the separating means, another separating means positioned to receive said first and second reflected beams, and first and second photodetector devices which respectively receive radiation extracted by said first and second separating means.
Claim 8
Dependent Claim
25 words
An interferometric optical device according to claim 1, wherein a spatial filter is arranged in at least one of the first and second beam paths.
Claim 9
Dependent Claim
33 words
An interferometric optical device according to claim 1, wherein means for polarising the laser radiation are provided for polarising the radiation propagating along at least one of the first and second beam paths.
Claim 10
Dependent Claim
18 words
An interferometric device according to claim 1, further comprising means for optically dephasing first and second beam paths.
Claim 11
Dependent Claim
56 words
An interferometric optical device according to claim 1, further comprising means for phase modulation of the laser radiation passing along at least one of the first and second beam paths, the modulation being carried out at a predetermined frequency, and means for synchronous demodulation at the same frequency as the signals provided by the comparison means.
Claim 12
Dependent Claim
30 words
An interferometric optical device according the claim 1, wherein the two phase conjugating mirror means are close to each other or are combined into a single phase conjugating mirror means.
Claim 13
Dependent Claim
24 words
An interferometric optical device according to claim 1, wherein at least one of the first and second beam paths forms at least one loop.
Claim 14
Dependent Claim
27 words
An interferometric optical device according to claim 1, wherein at least one of the first and second beam paths is at least partially defined by fibre optics.
Claim 15
Dependent Claim
15 words
An interferometric optical device according to claim 13 wherein the fiber optics are multimode fibers.
Claim 16
Dependent Claim
35 words
An interferometric optical device according to claim 1, wherein the first and second beam paths form two substantially closed circuits which are substantially of the same geometry and which are spatially close to each other.
References Cited (Backward Citations)
US4198162A
Cited
FR2446482A1
Cited
FR2449897A1
Cited
EP0026128A1
Cited
US4280764A
Cited
US4429393A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-03-10 | 1989-09-09 | 1990-03-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-03-10 | 1993-09-09 | 1994-03-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-03-10 | 1997-09-09 | 1998-03-11 | $7700.00 | Window Closed / Lapsed |