US5201015A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Conformal fiber optic strain sensor
Assignee: Northrop Grumman Guidance and Electronics Co Inc
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Filing: 1991-09-19
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Granted: 1993-04-06
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Expires: 2011-09-19
Abstract
Abstract A length of optical fiber is attached to a flexible base plate at two spaced apart locations. The portion of the fiber between the two points of connection is under a bias tension. An interferometer is formed in the tensioned portion of the optical fiber. The sensor is mounted to a surface and changes in interference patterns output by the interferometer are monitored to measure strain in the surface.
Inventors
- 👤 Karlheinz Von Bieren
- 👤 Akbar Arabsadeghabadi
- 👤 Phillip Skochinski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 12:07
CPC Classifications
G; G01; G01B; G01B11/00; G01B11/16; G01D; G01D5/00; G01D5/26; G01D5/32; G01D5/34; G01D5/353; G01D5/35303; G01L; G01L1/00; G01L1/24; G01L1/242
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
100 words
A fiber optic strain sensor for measuring strains along a curved surface, comprising: a flexible base plate; a length of optical fiber attached to the base plate at two spaced apart locations with a sensing portion of the optical fiber being between the two spaced apart locations, the base plate having a concave portion formed therein between the two spaced apart locations such that the base plate has a tendency to straighten itself, thereby applying a bias tension to the sensing portion of the optical fiber; and means for forming an interferometer in the sensing portion of the optical fiber.
Claim 2
Dependent Claim
100 words
A fiber optic strain sensor for measuring strains along a curved surface, comprising: a flexible base plate; a length of optical fiber attached to the base plate at two spaced apart locations with a sensing portion of the optical fiber being between the two spaced apart locations, the base plate having a concave portion formed therein between the two spaced apart locations such that the base plate has a tendency to straighten itself, thereby applying a bias tension to the sensing portion of the optical fiber; and means for forming an interferometer in the sensing portion of the optical fiber.
Claim 3
Dependent Claim
22 words
The fiber optic strain sensor of claim 1 wherein a Mach-Zehnder interferometer is formed in the sensing portion of the optical fiber.
Claim 4
Dependent Claim
74 words
A fiber optic strain sensor for measuring strains along a curved surface, comprising: a flexible base plate; a length of optical fiber attached to the base plate at two spaced apart locations with a sensing portion of the optical fiber being between the two spaced apart locations; means for applying a bias tension to the sensing portion of the optical fiber; and a Michelson interferometer formed in the sensing portion of the optical fiber.
Claim 5
Dependent Claim
74 words
A fiber optic strain sensor for measuring strains along a curved surface, comprising: a flexible base plate; a length of optical fiber attached to the base plate at two spaced apart locations with a sensing portion of the optical fiber being between the two spaced apart locations; means for applying a bias tension to the sensing portion of the optical fiber; and a Michelson interferometer formed in the sensing portion of the optical fiber.
Claim 6
Independent Claim
94 words
A method for forming a fiber optic strain sensor, comprising the steps of: providing a flexible base plate; attaching a length of optical fiber to the base plate at two spaced apart locations with a sensing portion of the optical fiber being between the two spaced apart locations; bending the base plate such that the base plate between the two spaced apart locations has a tendency to straighten itself, thereby applying a bias tension to the sensing portion of the optical fiber; and forming an interferometer in the sensing portion of the optical fiber.
Claim 7
Independent Claim
94 words
A method for forming a fiber optic strain sensor, comprising the steps of: providing a flexible base plate; attaching a length of optical fiber to the base plate at two spaced apart locations with a sensing portion of the optical fiber being between the two spaced apart locations; bending the base plate such that the base plate between the two spaced apart locations has a tendency to straighten itself, thereby applying a bias tension to the sensing portion of the optical fiber; and forming an interferometer in the sensing portion of the optical fiber.
Claim 8
Dependent Claim
24 words
The fiber optic strain sensor of claim 4 including the step of forming a Mach-Zehnder interferometer in the sensing portion of the optical fiber.
Claim 9
Independent Claim
130 words
A method for forming a fiber optic strain sensor, comprising the steps of: providing a flexible base plate; attaching a length of optical fiber to the base plate at two spaced apart locations with a sensing portion of the optical fiber being between the two spaced apart locations; applying a bias tension to the sensing portion of the optical fiber by the steps of: bending a central portion of the base plate; fixing the optical fiber to the base plate with the two spaced apart locations being on opposite sides of the central portion; and straightening the base plate so that the portion of the optical fiber that is between the two spaced apart locations is under tension; and forming an interferometer in the sensing portion of the optical fiber.
Claim 10
Independent Claim
130 words
A method for forming a fiber optic strain sensor, comprising the steps of: providing a flexible base plate; attaching a length of optical fiber to the base plate at two spaced apart locations with a sensing portion of the optical fiber being between the two spaced apart locations; applying a bias tension to the sensing portion of the optical fiber by the steps of: bending a central portion of the base plate; fixing the optical fiber to the base plate with the two spaced apart locations being on opposite sides of the central portion; and straightening the base plate so that the portion of the optical fiber that is between the two spaced apart locations is under tension; and forming an interferometer in the sensing portion of the optical fiber.
Claim 11
Independent Claim
73 words
A method for forming a fiber optic strain sensor including the steps of: providing a flexible base plate; attaching a length of optical fiber to the base plate at two spaced apart locations with a sensing portion of the optical fiber being between the two spaced apart locations; applying a bias tension to the sensing portion of the optical fiber; and forming a Michelson interferometer in the sensing portion of the optical fiber.
Claim 12
Independent Claim
73 words
A method for forming a fiber optic strain sensor including the steps of: providing a flexible base plate; attaching a length of optical fiber to the base plate at two spaced apart locations with a sensing portion of the optical fiber being between the two spaced apart locations; applying a bias tension to the sensing portion of the optical fiber; and forming a Michelson interferometer in the sensing portion of the optical fiber.
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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) | 1996-04-05 | 1996-10-05 | 1997-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-04-05 | 2000-10-05 | 2001-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-04-05 | 2004-10-05 | 2005-04-06 | $7700.00 | Window Closed / Lapsed |