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US4456377A
Expired / Lapsed
US
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Multimode fiber optic rotation sensor
Assignee: Leland Stanford Junior University
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Filing: 1981-11-06
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Granted: 1984-06-26
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Expires: 2001-11-06
Abstract
Abstract A fiber optic rotation sensor utilizes multimode optical fiber to improve power coupling and reduce coherent back scattering. A multimode light source such as a light emitting diode can be used. The system is economical and environmentally stable.
Inventors
- 👤 H. John Shaw
- 👤 George A. Pavlath
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:45
CPC Classifications
G; G01; G01C; G01C19/00; G01C19/58; G01C19/64; G01C19/72
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
88 words
A fiber optic rotation sensor comprising: a source of light for producing spatially incoherent light; a coil of multimode optical fiber, means for applying two lightwaves from said source of light through said coil in opposite directions, such that the optical power of said lightwaves is substantially evenly divided among the modes of said multimode fiber; means for recombining said two lightwaves after passing through said coil, and means for detecting substantially all of the modes of said recombined waves to determine phase shift between said two lightwaves.
Claim 2
Dependent Claim
88 words
A fiber optic rotation sensor comprising: a source of light for producing spatially incoherent light; a coil of multimode optical fiber, means for applying two lightwaves from said source of light through said coil in opposite directions, such that the optical power of said lightwaves is substantially evenly divided among the modes of said multimode fiber; means for recombining said two lightwaves after passing through said coil, and means for detecting substantially all of the modes of said recombined waves to determine phase shift between said two lightwaves.
Claim 3
Dependent Claim
19 words
The fiber optic rotation sensor as defined by claim 1 wherein said light source comprises a multimode light source.
Claim 4
Dependent Claim
19 words
The fiber optic rotation sensor as defined by claim 2 wherein said light source comprises a light emitting diode.
Claim 5
Dependent Claim
34 words
The fiber optic rotation sensor as defined by claim 1 wherein said means for applying two light beams includes phase shift means for shifting the phase of one of said light beams by 90°.
References Cited (Backward Citations)
US3102953A
Cited
US3395270A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-06-26 | 1987-12-26 | 1988-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-06-26 | 1991-12-26 | 1992-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-06-26 | 1995-12-26 | 1996-06-26 | $7700.00 | Window Closed / Lapsed |