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Analysis Of Fiber Bragg Gratings For Ultrasonic Detection, Tongqing Liu

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Fiber optic sensors became an emerging technique to detect ultrasonic emissions in the last decade. Their light weight, immunity to electromagnetic interference and capacity of being multiplexed make them defeat their electronic counterparts in various applications. In this thesis we presented a novel fiber optic ultrasonic sensor based on pi phase shift fiber Bragg gratings. Numerical simulations were performed to study the characteristics of pi phase shift fiber Bragg gratings impinged by ultrasonic waves. The coupling theory was introduced to analyze the change of fiber Bragg gratings when impinged by ultrasonic waves, and the transfer matrix method was utilized to …