Optics: measuring and testing – For optical fiber or waveguide inspection
Reexamination Certificate
2007-04-03
2007-04-03
Nguyen, Tu T. (Department: 2877)
Optics: measuring and testing
For optical fiber or waveguide inspection
Reexamination Certificate
active
10696766
ABSTRACT:
A method and apparatus sense attributes of reflected signals in an optical sensing system. In one embodiment, a method for sensing in an optical sensing system comprising an interrogator coupled to a Bragg grating sensor by an optical cable includes the steps of producing a first optical signal, coupling the first optical signal to an optical cable, receiving a first reflected signal from a Bragg grating sensor within the optical cable, resolving a wavelength of first reflected signal, producing a second optical signal, coupling the second optical signal to the optical cable, receiving a second reflected signal caused by Brillouin backscattering within the optical cable, and resolving a difference in frequencies between the second optical signal and second reflected signal. Embodiments of the method and apparatus are particularly useful for sensing temperature and strain in hazardous locations such as down hole gas and oil field applications and the like.
REFERENCES:
patent: 4767219 (1988-08-01), Bibby
patent: 5483607 (1996-01-01), O'Keefe
patent: 6298184 (2001-10-01), Putnam et al.
patent: 6363089 (2002-03-01), Fernald et al.
patent: 6404961 (2002-06-01), Bonja et al.
patent: 6422084 (2002-07-01), Fernald et al.
patent: 6452667 (2002-09-01), Fernald et al.
patent: 6519388 (2003-02-01), Fernald et al.
patent: 6555807 (2003-04-01), Clayton et al.
patent: 2003/0234921 (2003-12-01), Yamate et al.
patent: 0 490 113 (2003-12-01), None
U.S. Appl. No. 10/422,396, filed Apr. 24, 2003, Dowd et al.
U.S. Appl. No. 10/397,754, filed Mar. 26, 2003, MacDougall.
Sakairi et al., “A System for Measuring Temperature and Strain Separately by BOTDR and OTDR”,Advanced Sensor Systems and Applications, Proceedings of SPIE vol. 4920, pp. 274-287 (2002) U.S.A.
Tanaka et al., “Polarization Dependence of Depolarized Guided Acoustic-Wave Brillouin Scattering Detected After an Analyzer”,Journal of Optical Communications, pp. 82-85 (2000) U.S.A.
Tanaka et al., “Polarization Dependence of Amplitude Modulation by Guided Acoustic-Wave Brillouin Scattering”, Department of Electrical and Electronic Engineering, Shizuoka University, SPIE vol. 3746, pp. 116-119 (1999) Japan.
Bao, “Tensile and Compressive Strain Measurement in the Lab and Field with the Distributed Brillouin Scattering Sensor”,Journal of Lightwave Technology, vol. 19, No. 11, pp. 1698-1704 (Nov. 2001) U.S.A.
P.C. Wait and A. H. Hartog, Spontaneous Brillouin-Based Distributed Temperature Sensor Utilizing a Fiber Bragg Grating Notch Filter for the Separation of the Brillouin Signal, IEEE Photonics Technology Letters, vol., 13, No. 5, May 2001.
CA Examiner's Report, Application No. 2,488,265, Dated Nov. 9, 2006.
Nguyen Tu T.
Patterson & Sheridan LLP
Weatherford / Lamb, Inc.
LandOfFree
Combined Bragg grating wavelength interrogator and Brillouin... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Combined Bragg grating wavelength interrogator and Brillouin..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Combined Bragg grating wavelength interrogator and Brillouin... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3756146