US5034679A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polarization feedback control of polarization rotating sensor
Assignee: Sundstrand Corp
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Filing: 1989-12-14
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Granted: 1991-07-23
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Expires: 2009-12-14
Abstract
Abstract A measuring system (40) for measuring a magnitude of a quantity in accordance with the invention includes a light source (52) for providing a light beam (58); a polarization controller (44), optically coupled to the light beam, for rotating a plane of polarization of the light beam through an angle in response to a control signal, which is proportional to the magnitude of the quantity being measured to provide a first rotated polarized beam of light; a sensor (46), coupled optically to the first rotated polarized beam of light and to the quantity being measured, which rotates the plane of polarization of the first rotated polarized beam through an angle proportional to the quantity being measured to provide a second rotated polarized beam of light; an analyzer (42), coupled optically to the second rotated polarized beam of light, having a constant plane of polarization for detecting the second rotated polarized beam of light produced by the quantity being measured; and a feedback and output circuit, coupled to an output of the analyzer, for providing an output proportional to magnitude of the quantity being measured and producing the control signal.
Inventors
- 👤 Eric A. Henderson
- 👤 Terrill G. Power
- 👤 Stephen R. Jones
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:03
CPC Classifications
G; G01; G01R; G01R15/00; G01R15/14; G01R15/24; G01D; G01D5/00; G01D5/26; G01D5/32; G01D5/34; G01D5/344; G01R33/00; G01R33/02; G01R33/032
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
217 words
A measuring system for measuring a magnitude of a quantity comprising: a light source for providing a light beam; a polarization controller, optically coupled to the light beam for rotating a plane of polarization of the light beam through an angle, in response to a control signal, which is proportional to the magnitude of the quantity being measured to provide a first rotated plane polarized beam of light; a sensor, coupled optically to the first rotated plane polarized beam of light and coupled to the quantity being measured, which rotates the plane of polarization of the first rotated plane polarized beam of light through an angle proportional to the quantity being measured to provide a second rotated plane polarized beam of light; an analyzer, coupled optically to the second rotated plane polarized beam of light, having a constant plane of polarization for detecting the second rotated polarized beam of light produced by the quantity; and a feedback and output circuit, coupled to an output of the analyzer, for providing an output of the magnitude of the quantity being measured and producing the control signal by calculating a difference between a signal proportional to the quantity being measured and a reference signal that is proportional to the magnitude of the light beam prior to application to the sensor.
Claim 2
Dependent Claim
217 words
A measuring system for measuring a magnitude of a quantity comprising: a light source for providing a light beam; a polarization controller, optically coupled to the light beam for rotating a plane of polarization of the light beam through an angle, in response to a control signal, which is proportional to the magnitude of the quantity being measured to provide a first rotated plane polarized beam of light; a sensor, coupled optically to the first rotated plane polarized beam of light and coupled to the quantity being measured, which rotates the plane of polarization of the first rotated plane polarized beam of light through an angle proportional to the quantity being measured to provide a second rotated plane polarized beam of light; an analyzer, coupled optically to the second rotated plane polarized beam of light, having a constant plane of polarization for detecting the second rotated polarized beam of light produced by the quantity; and a feedback and output circuit, coupled to an output of the analyzer, for providing an output of the magnitude of the quantity being measured and producing the control signal by calculating a difference between a signal proportional to the quantity being measured and a reference signal that is proportional to the magnitude of the light beam prior to application to the sensor.
Claim 3
Dependent Claim
21 words
A measuring system in accordance with claim 1 wherein: the reference signal is provided from a driver of the light source.
Claim 4
Dependent Claim
34 words
A measuring system in accordance with claim 1 wherein: the reference signal is provided from a photodetector optically coupled to an optical coupler optically coupled to the first rotated polarized beam of the light.
Claim 5
Dependent Claim
69 words
A measuring system further in accordance with claim 1 wherein: the analyzer polarizes the second rotated plane polarized beam of light with a fixed rotation to provide a first output light beam; and a first photodetector is optically coupled to the first output light beam and produces a first signal proportional to an intensity of the first output light beam which is coupled to the feedback and output circuit.
Claim 6
Dependent Claim
68 words
A measuring system in accordance with claim 4 wherein: the analyzer further polarizes the second rotated polarized beam of light with a fixed polarization to provide a second output light beam; and a second photodetector is optically coupled to the second output light beam and produces a second signal proportional to an intensity of the second output light beam which is coupled to the feedback and output circuit.
Claim 7
Dependent Claim
68 words
A measuring system in accordance with claim 1 wherein: the analyzer further polarizes the second rotated polarized beam of light with a fixed polarization to provide a second output light beam; and a second photodetector is optically coupled to the second output light beam and produces a second signal proportional to an intensity of the second output light beam which is coupled to the feedback and output circuit.
Claim 8
Dependent Claim
68 words
A measuring system in accordance with claim 1 wherein: the analyzer further polarizes the second rotated polarized beam of light with a fixed polarization to provide a second output light beam; and a second photodetector is optically coupled to the second output light beam and produces a second signal proportional to an intensity of the second output light beam which is coupled to the feedback and output circuit.
Claim 9
Dependent Claim
66 words
A measuring system in accordance with claim 3 wherein: analyzer polarizes the second rotated polarized beam of light with a fixed rotation to provide a first output light beam; and a first photodetector is optically coupled to the first output light beam and produces a first signal proportional to an intensity of the first output light beam which is coupled to the feedback and output circuit.
Claim 10
Dependent Claim
17 words
A measuring system in accordance with claim 1 wherein: the polarization controller is a waveguide electro-optic crystal.
Claim 11
Dependent Claim
16 words
A measuring system in accordance with claim 1 wherein: the polarization controller is a fiber squeezer.
Claim 12
Dependent Claim
16 words
A measuring system in accordance with claim 1 wherein: the polarization controller is a fiber coil.
Claim 13
Dependent Claim
16 words
A measuring system in accordance with claim 1 wherein: the polarization controller is a phase plate.
Claim 14
Dependent Claim
16 words
A measuring system in accordance with claim 1 wherein: the polarization controller is a Faraday rotator.
Claim 15
Dependent Claim
16 words
A measuring system in accordance with claim 1 wherein: the polarization controller is a rotatable crank.
Claim 16
Dependent Claim
16 words
A measuring system in accordance with claim 1 wherein: the polarization controller is a Kerr cell.
Claim 17
Dependent Claim
16 words
A measuring system in accordance with claim 1 wherein: the polarization controller is a Pockels cell.
Claim 18
Dependent Claim
23 words
A measuring system in accordance with claim 1 wherein: the quantity being measured is current; and the sensor utilizes the magneto optic effect.
Claim 19
Dependent Claim
24 words
A measuring system in accordance with claim 1 wherein: the quantity being measured is magnetic field strength; and the sensor utilizes the magneto-optic effect.
Claim 20
Dependent Claim
22 words
A measuring system in accordance with claim 1 wherein: the quantity being measured is voltage; and the sensor utilizes the electro-optic effect.
Claim 21
Dependent Claim
22 words
A measuring system in accordance with claim 1 wherein: the quantity being measured is pressure; and the sensor utilizes the photoelastic effect.
References Cited (Backward Citations)
US3466541A
Cited
US4542338A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-07-22 | 1995-01-21 | 1995-07-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-07-22 | 1999-01-21 | 1999-07-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-07-22 | 2003-01-21 | 2003-07-23 | $7700.00 | Window Closed / Lapsed |