USH371H
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical fiber interferometer
Assignee: United States Department of the Navy
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Filing: 1987-01-14
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Granted: 1987-11-03
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Expires: 2007-01-14
Abstract
Abstract A sensor system is disclosed for measuring small physical perturbations inhe environment using an optical fiber interferometer in the Fabry-Perot configuration operating at maximum sensitivity. A single frequency laser source is focused on one end of a single mode optical fiber with highly polished, highly reflective flat ends. An element responsive to the ambient magnetic or electric field alters the fiber's optical path length, thereby affecting the intensity of light transmitted through the fiber. A detection and feedback system detects the transmitted light and readjusts the optical path length to one which corresponds to maximum sensitivity.
Inventors
- 👤 Lloyd C. Bobb
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 03:43
CPC Classifications
G; G01; G01R; G01R15/00; G01R15/14; G01R15/24; G01R15/248; G01D; G01D5/00; G01D5/26; G01D5/32; G01D5/34; G01D5/353; G01D5/35306; G01D5/35309; G01D5/35312; G01R33/00; G01R33/02; G01R33/032; G01R33/0327
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
157 words
An optical fiber interferometer for measuring environmental perturbations comprising: a source of coherent light; a length of optical fiber having two flat ends perpendicular to the axis of said fiber at said ends, said fiber being operatively connected to transmit the light received through one of said ends; detecting means operatively connected to receive the transmitted light from the other of said ends for detecting the intensity of the received light and for producing a signal indicative thereof; sensing means operatively connected to said fiber for modulating the optical path length of the light in said fiber in response to an environmental perturbation; feedback means operatively connected to said detecting means for receiving the signal therefrom and producing a current at said sensing means for adjusting the optical path length in response to the signal; and display means operatively connected to said feedback means for measuring the current and displaying a value indicative of the corresponding perturbation.
Claim 2
Dependent Claim
157 words
An optical fiber interferometer for measuring environmental perturbations comprising: a source of coherent light; a length of optical fiber having two flat ends perpendicular to the axis of said fiber at said ends, said fiber being operatively connected to transmit the light received through one of said ends; detecting means operatively connected to receive the transmitted light from the other of said ends for detecting the intensity of the received light and for producing a signal indicative thereof; sensing means operatively connected to said fiber for modulating the optical path length of the light in said fiber in response to an environmental perturbation; feedback means operatively connected to said detecting means for receiving the signal therefrom and producing a current at said sensing means for adjusting the optical path length in response to the signal; and display means operatively connected to said feedback means for measuring the current and displaying a value indicative of the corresponding perturbation.
Claim 3
Dependent Claim
14 words
An optical fiber interferometer according to claim 1 wherein said fiber is single mode.
Claim 4
Dependent Claim
15 words
An optical fiber interferometer according to claim 1 wherein said flat ends are partially reflective.
Claim 5
Dependent Claim
24 words
An optical fiber interferometer according to claim 1 wherein said sensing means comprises a magnetostrictive element responsive to changes in ambient magnetic field strength.
Claim 6
Dependent Claim
46 words
An optical fiber interferometer according to claim 4 wherein said feedback means comprises: electronic means operatively connected to receive and amplify the signal; and a coil about said element operatively connected to receive the amplified signal and create a magnetic field adjacent to said magnetostrictive element.
Claim 7
Dependent Claim
24 words
An optical fiber interferometer according to claim 1 wherein said sensing means comprises a piezoelectric element responsive to changes in ambient electric field strength.
Claim 8
Dependent Claim
41 words
An optical fiber interferometer according to claim 6 wherein said feedback means comprises: electronic means operatively connected for receiving the signal from said detecting means; and circuitry operatively connected to said electronic means for passing a current through said piezoelectric element.
Claim 9
Dependent Claim
180 words
An optical fiber interferometer for measuring change in magnetic field, comprising: a source of coherent light; a length of single mode optical fiber having two partially reflective flat ends, said fiber being optically connected to transmit the light received through one of said ends; detecting means optically connected to receive the transmitted light from the other of said fiber ends for detecting the intensity of the received light and producing a signal indicative thereof; a magnetostrictive element operatively connected to said fiber for changing the length of said fiber in response to a magnetic field, thereby altering the optical path length of said fiber and changing the interference condition and therefore the intensity of the light received by said detecting means; feedback means operatively connected to said detecting means for receiving the signal therefrom and producing a current to said element for adjusting the length of said fiber in response to the signal; and display means operatively connected to said feedback means for receiving a portion of the current therefrom and displaying a value indicative of the corresponding magnetic field.
Claim 10
Dependent Claim
180 words
An optical fiber interferometer for measuring change in magnetic field, comprising: a source of coherent light; a length of single mode optical fiber having two partially reflective flat ends, said fiber being optically connected to transmit the light received through one of said ends; detecting means optically connected to receive the transmitted light from the other of said fiber ends for detecting the intensity of the received light and producing a signal indicative thereof; a magnetostrictive element operatively connected to said fiber for changing the length of said fiber in response to a magnetic field, thereby altering the optical path length of said fiber and changing the interference condition and therefore the intensity of the light received by said detecting means; feedback means operatively connected to said detecting means for receiving the signal therefrom and producing a current to said element for adjusting the length of said fiber in response to the signal; and display means operatively connected to said feedback means for receiving a portion of the current therefrom and displaying a value indicative of the corresponding magnetic field.
Claim 11
Dependent Claim
46 words
An optical fiber interferometer according to claim 8 wherein said feedback means comprises: electronic means operatively connected to receive and amplify the signal; and a coil about said element operatively connected to receive the amplified signal and create a magnetic field adjacent to said magnetostrictive element.
Claim 12
Dependent Claim
180 words
An optical fiber interferometer for measuring change in electric field, comprising: a source of coherent light; a length of single mode optical fiber having two partially reflective flat ends, said fiber being optically connected to transmit the light received through one of said ends; detecting means optically connected to receive the transmitted light from the other of said fiber ends for detecting the intensity of the received light and producing a signal indicative thereof; a piezoelectric element operatively connected to said fiber for changing the length of said fiber in response to an electric field, thereby altering the optical path length of said fiber and changing the interference condition and therefore the intensity of the light received by said detecting means; feedback means operatively connected to said detecting means for receiving the signal therefrom and producing a current to said element for adjusting the length of said fiber in response to the signal; and display means operatively connected to said feedback means for receiving a portion of the current therefrom and displaying a value indicative of the corresponding electric field.
Claim 13
Dependent Claim
180 words
An optical fiber interferometer for measuring change in electric field, comprising: a source of coherent light; a length of single mode optical fiber having two partially reflective flat ends, said fiber being optically connected to transmit the light received through one of said ends; detecting means optically connected to receive the transmitted light from the other of said fiber ends for detecting the intensity of the received light and producing a signal indicative thereof; a piezoelectric element operatively connected to said fiber for changing the length of said fiber in response to an electric field, thereby altering the optical path length of said fiber and changing the interference condition and therefore the intensity of the light received by said detecting means; feedback means operatively connected to said detecting means for receiving the signal therefrom and producing a current to said element for adjusting the length of said fiber in response to the signal; and display means operatively connected to said feedback means for receiving a portion of the current therefrom and displaying a value indicative of the corresponding electric field.
Claim 14
Dependent Claim
41 words
An optical fiber interferometer according to claim 10 wherein said feedback means comprises: electronic means operatively connected for receiving the signal from said detecting means; and circuitry operatively connected to said electronic means for passing a current through said piezoelectric element.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-11-02 | 1991-05-04 | 1991-11-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-11-02 | 1995-05-04 | 1995-11-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-11-02 | 1999-05-04 | 1999-11-03 | $7700.00 | Window Closed / Lapsed |