Optical waveguides – Optical waveguide sensor
Patent
1997-04-18
1998-07-07
Palmer, Phan T.H.
Optical waveguides
Optical waveguide sensor
385 13, 385 11, 385 28, 25022714, 25022715, G02B 600
Patent
active
057781141
ABSTRACT:
A Fiber Analysis System (10) detects threats to a buried underground fiber (10) by delivering two optical sub-signals, split from a single beam, into opposite ends of the fiber so the sub-signals traverse the fiber in opposite directions. The sub-signals are recombined into a beam whose characteristics are detected by a detector (24). The output signal of the detector (24) is compared by a processor (26) to different reference values stored in a data base (28) representing different detector output signals corresponding to different fiber conditions. By matching the detector output signal to a reference value associated with a particular fiber condition, the processor can determine whether a potential threat exists. By inducing a sequence of known vibrations (tones) inn the fiber at spaced locations along a generally orthogonal to the fiber (12), the processor (26) can establish the location of the fiber by comparing the detector output signal to a reference signals corresponding to the known tones to determine which one was received in the shortest time.
REFERENCES:
patent: 4904050 (1990-02-01), Dunn et al.
patent: 5483607 (1996-01-01), O'Keefe
patent: 5694497 (1997-12-01), Sansone
Eric Udd, Fiber Optic Sensors Based on the Sagnac Interferometer and Passive Ring Resonator, pp. 233-269. Fiber Optic Sensors: An Introduction for Engineers and Scientists, Edited by Eric Udd. ISBN 0-471-83007-0, 1991 John Wiley & Sons, Inc.
The Photonics Dictionary, Book 4, 41st International Edition 1995, Absolute Optical Testing: Computers, Interferometers Combine for More Acurate Optical Tests, James C. Wyant; Fringes, Waves, Optical Quality: Understanding Where Fringes Come from and Their Roles in Quality, Bruce H. Walker (Walker Associates).
A. Yu, A.S. Siddiqui, Optical Modulators Using Fibreoptic Sagnac Interferometers, Paper 9806J (E13), first received 14th Oct. 1992 and in revised form 2nd Mar. 1993. IEE Proc.-Optoelectron., vol. 141, No. 1, Feb. 1994, pp. 1-7.
Mieczyslaw Szustakowski, Leszek R. Jaroszewica, Detection of the phase disturbance in fibre optic Sagnac interferometer; SPIE vol. 2341 Interferometric Fiber Sensing (1994), pp. 74-88.
GRI-FOIDS Report, Appendix B, Submitted by Mason & Hanger National, Inc., 260 Finney Drive, Huntsville, AL 35824, Aug. 1995, Approved: NICOR Technologies Inc., pp. 1-23.
GRI-FOIDS Test Plan, Appendix 1, Submitted By: Mason & Hanger National, Inc., 260 Finney Drive, Huntsville, AL 35824, May 1995.
Field Evaluation of a Fiber Optic Intrusion Detection System--FOIDS, Prepared by: NICOR Technologies, Inc.
Eslambolchi Hossein
Huffman John Sinclair
Levy Robert B.
Palmer Phan T.H.
LandOfFree
Fiber analysis method and apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Fiber analysis method and apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fiber analysis method and apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1215445