US4969017A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Measuring device for the measurement, in a wide range, of a non-reciprocal phase shift generated in a ring interferometer, and measuring method
Assignee: Callahan Cellular LLC
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Filing: 1989-06-01
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Granted: 1990-11-06
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Expires: 2009-06-01
Abstract
Abstract The disclosure pertains to a device for the measurement, in a wide range, of a non-reciprocal phase shift generated in a ring interferometer, to a measuring method and, chiefly , to an optic fiber gyrometer. It also concerns a method of measurement, notably a method for the measurement of rotation speed. The disclosure concerns an improvement in a measuring device comprising a phase modulation device enabling the phase to be automatically locked to an interference fringe of the device. The improvement lies mainly in the fact that the light source emits, in the ring, several light frequencies so as to make it possible to remove uncertainty on the order (0, π, 2π, etc.) of the interference fringe on which the automatic control is achieved. The disclosure can be applied notably to the making of devices for the measurement of angular speeds. The disclosure can be aplied chiefly to the making of optic fiber gyrometers.
Inventors
- 👤 Herve Lefevre
- 👤 Marc Turpin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 13:23
CPC Classifications
G; G01; G01C; G01C19/00; G01C19/58; G01C19/64; G01C19/72; G01C19/726
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
116 words
A system for measuring non-reciprocal phase shift generated in a ring interferometer comprising: a source of coherent light; means located in optical alignment with the ring interferometer for shifting the phase of light emitted therefrom; modulation means connected to the source for causing simultaneous emission therefrom of at least two light signals at different frequencies, one of which is a central frequency; means for measuring the difference in amplitude of the signals which determines the depth of modulation and thus the corresponding order of an interference fringe at which the phase-shifting means operates; and means for compensating the phase-shifted light emitted by the ring interferometer by a value dependent upon the order of the interference fringe.
Claim 2
Independent Claim
116 words
A system for measuring non-reciprocal phase shift generated in a ring interferometer comprising: a source of coherent light; means located in optical alignment with the ring interferometer for shifting the phase of light emitted therefrom; modulation means connected to the source for causing simultaneous emission therefrom of at least two light signals at different frequencies, one of which is a central frequency; means for measuring the difference in amplitude of the signals which determines the depth of modulation and thus the corresponding order of an interference fringe at which the phase-shifting means operates; and means for compensating the phase-shifted light emitted by the ring interferometer by a value dependent upon the order of the interference fringe.
Claim 3
Dependent Claim
31 words
The structure set forth in claim 1 wherein the modulation means causes simultaneous emission from the source of three light signals at different frequencies, one of which is a central frequency.
Claim 4
Dependent Claim
25 words
The structure set forth in claim 2 wherein the measuring means measures amplitude difference between two signals other than the signal at the central frequency.
Claim 5
Dependent Claim
130 words
In a method for the measurement of a non-reciprocal phase shift in a ring interferometer by comparing the phases of light signals traveling in opposite directions through the ring, the method comprising the steps: generating a coherent beam of light for travel through the ring in opposite directions; shifting the phase of light emitted from the ring; modulating the light for causing simultaneous emission therefrom of at least two light signals at different frequencies, one of which is a central frequency; measuring the difference in amplitude of the signals which determines the depth of modulation and thus the corresponding order of an interference fringe at which the phase-shift occurs; and compensating the phase-shifted light emitted by the ring interferometer by a value dependent upon the order of the interference fringe.
Claim 6
Dependent Claim
130 words
In a method for the measurement of a non-reciprocal phase shift in a ring interferometer by comparing the phases of light signals traveling in opposite directions through the ring, the method comprising the steps: generating a coherent beam of light for travel through the ring in opposite directions; shifting the phase of light emitted from the ring; modulating the light for causing simultaneous emission therefrom of at least two light signals at different frequencies, one of which is a central frequency; measuring the difference in amplitude of the signals which determines the depth of modulation and thus the corresponding order of an interference fringe at which the phase-shift occurs; and compensating the phase-shifted light emitted by the ring interferometer by a value dependent upon the order of the interference fringe.
Claim 7
Dependent Claim
31 words
The method set forth in claim 4 wherein the modulation step causes simultaneous emission from the source of three light signals at difference frequencies, one of which is a central frequency.
Claim 8
Dependent Claim
26 words
The method set forth in claim 4 wherein the measuring step measures the amplitude difference between two signals other than the signal at the central frequency.
References Cited (Backward Citations)
US4834538A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-11-05 | 1994-05-07 | 1994-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-11-05 | 1998-05-07 | 1998-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-11-05 | 2002-05-07 | 2002-11-06 | $7700.00 | Window Closed / Lapsed |