Micro-optical sensor system for pressure, acceleration, and pressure gradient measurements
Patent 7428054 Issued on September 23, 2008. Estimated Expiration Date: January 21, 2025. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
A micro-optical fiber tip based sensor system for pressure, acceleration, and pressure gradient measurements in a wide bandwidth, the design of which allows for multiplexity of the input side of the system is based on micro-electromechanical fabrication techniques. The optical portion of the system is based on low coherence fiber-optic interferometry techniques which has a sensor Fabry-Perot interferometer and a read-out interferometer combination that allows a high dynamic range and low sensitivity to the wavelength fluctuation of the light source. A phase modulation and demodulation scheme takes advantage of the Integrated Optical Circuit phase modulator and multi-step phase-stepping algorithm for providing high frequency and real time phase signal demodulation. The system includes fiber tip based Fabry-Perot sensors each of which has a diaphragm that is used as a transducer.
Other References
M. Yu, et al., “Fiber Tip Based Fiber Optic Acoustic Sensors”, Twelfth International Conference on Adaptive Structures, Eds. N. Wereley, et al., CRC Press, 245-254, 2001.
R. Claus, et a., Editors, “Sensory Phenomena and Measurement Instrumentation for Smart Structures and Materials”, Proceedings of SPIE, Mar. 1-4, 1999 Newport Beach, California, vol. 3670, pp. 342-351, 1999.
P. Beard, et al., “Characterization of a Polymer Film Optical Fiber Hydrophone for Use in the Range 1 to 20 MHz: A Comparison with PVDF Needle and Membrance Hydrophones”, IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, vol. 47, No. 1, pp. 256-264, Jan. 2000.
C. Koch, “Measurement of ultrasonic pressure by heterodyne interferometry with a fiber-tip sensor”, Applied Optics, vol. 38, No. 13, pp. 2812-2819, May 1, 1999.
D. Li, et al., “The ring-type all-fiber Fabry-Perot interferometer hydrophone system”, J. Acoust. Soc. Am., 104 (5), pp. 2798-2806, Nov. 1998.
C. Zhou, et al., “Fiber-optic microphone based on a combination of Fabry-Perot interferometry and intensity modulation”, J. Acoust. Soc. Am., 98 (2), Pt. 1, pp. 1042-1045, Aug. 1995.
G. He, et al., “The analysis of noises in a fiber optic microphone”, J. Acoust. Soc. Am., 92 (5), pp. 2521-2526, Nov. 1992.
C. Hess, “Optical microphone for the detection of hidden helicopters”, AIAA Journal, vol. 30, No. 11, pp. 2626-2631, Nov. 1992.
B. Balachandran and M. X. Zhao, “Actuator nonlinearities in interior acoustics control,” in Proceedings of SPIE Smart Structures and Materials 2000: Mathematics and Control in Smart Structures, pp. 101-109, Mar. 2000.
L.E. Kinsler, et al., “Fundamentals of Acoustics”, Second Edition, John Wiley & Sons, Inc., New York, 1962.
J.W. Parkins, “Active Minimization of Energy Density in a Three-Dimensional Enclosure”, Ph.D. Dissertation, Pennsylvania State University, 1998.
Baldwin, et al., “Bragg Grating Based Fabry-Perot Sensor System for Acoustic Measurements”, Proceedings of the SPIE 1999 Symposium on Smart Structures and Materials, Newport Beach, CA, Mar. 1-5, 1999.
Cole, J.H., et al., “Fiber Optic Detection of Sound”, Journal of Acoustic Society of America, 62, pp. 1136-1138, 1977.
Bucarco J.A., et al., “Fiber Optic Hydrophone”, Journal of Acoustical Society of America, 62, pp. 1302-1304, 1977.
M. Al-Bassyiouni, et al., “Experimental Studies of Zero Spillover Scheme for Active Structural Acoustic Control Systems”, Proceedings of the 12th International Conference on Adaptive Structures and Technologies (ICAST), University of Maryland, College Park, MD, Oct. 15-17, 2001.
M. Al-Bassyiouni, et al., “Zero Spillover Control of Enclosed Sound Fields”, SPIE's Annual International Symposium of Smart Structures and Materials, Newport Beach, CA, Mar. 4-8, vol. 4362, Paper No. 4326-7, 2001.
A. Sampath, et al., “Active Control of Multiple Tones Transmitted in an Enclosure”, Journal of the Acoustical Society of America, vol. 106, No. 1, pp. 211-225, Jul. 1999.