Radiant energy – Photocells; circuits and apparatus – Optical or pre-photocell system
Reexamination Certificate
2006-10-31
2006-10-31
Allen, Stephone B. (Department: 2878)
Radiant energy
Photocells; circuits and apparatus
Optical or pre-photocell system
C250S231100, C385S012000
Reexamination Certificate
active
07129470
ABSTRACT:
Disclosed herein is an optical sensor design and method for continually interrogating that sensor to produce an accurate representation of a dynamic event (such as a change in strain, pressure or temperature) being monitored by the sensor. The sensor design preferably constitutes continuous wave optical source/detection equipment coupled in series to a first fiber Bragg grating (FBG), a long period grating (LPG), and a second FBG formed in an optical waveguide. The LPG broadly attenuates light in the vicinity of the Bragg reflection wavelength λ2Bof the second FBG, and this attenuation profile shifts in wavelength in accordance with the dynamic event being monitored. Perturbation of the attenuation profile thus attenuates the intensity of the light reflected from the second FBG, i.e., I(λB2), because such reflected light must pass (twice) through the LPG. Accordingly, continually monitoring I(λB2) as a function of time allows the dynamic event to be recreated and processed accordingly. If necessary, I(λB2) can be normalized by dividing it by the intensity of the Bragg reflection wavelength from the first FBG, I(λB1), to discard attenuation within the system not related to the dynamic event being monitored.
REFERENCES:
patent: 5945666 (1999-08-01), Kersey et al.
patent: 6422084 (2002-07-01), Fernald et al.
patent: 6439055 (2002-08-01), Maron et al.
patent: 6785004 (2004-08-01), Kersey et al.
patent: 6931188 (2005-08-01), Kersey et al.
patent: 6955085 (2005-10-01), Jones et al.
patent: 2 348 000 (2000-09-01), None
patent: 2 402 740 (2004-06-01), None
U.K. Search Report, Application No. GB0411875.8, dated Sep. 23, 2004.
U.S. Appl. No. 09/726,059, filed Nov. 29, 2000, Kersey et al.
U.S. Appl. No. 10/371,910, filed Feb. 21, 2003, Kersey et al.
GB Examination Report, Application No. GB0411875.8, dated Oct. 25, 2006.
Allen Stephone B.
Patterson & Sheridan LLP
Weatherford / Lamb, Inc.
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