High-sensitivity ultrasonic phase-shifted fiber Bragg grating balanced sensing system.

A high-sensitivity ultrasonic sensing system is proposed and demonstrated. In this system, a phase-shifted fiber Bragg grating (PS-FBG) is used as a sensor to achieve broadband and highly sensitive detection. The PS-FBG modulates the output of a tunable laser to detect the ultrasonic strain directly. Balanced photo-detector (BPD) is used for eliminating the DC component and further amplifying the AC component in the detected signal. Another major function of the BPD is to reject laser intensity noise. As a result, the minimum detectable strain is limited by the BPD's noise and laser frequency noise. The sensitivity of the system is 9 nε/Hz(1/2). Because of its high sensitivity, this system has the potential to be used in acousto-ultrasonic testing without amplifying the input signal and in practical acoustic emission detection.

[1]  W. Jin.  Investigation of interferometric noise in fiber-optic bragg grating sensors by use of tunable laser sources. , 1998, Applied optics.

[2]  Ming C. Wu,et al.  Distributed balanced photodetectors for broad-band noise suppression , 1999 .

[3]  Moshe Tur,et al.  Static fiber-Bragg grating strain sensing using frequency-locked lasers , 1999 .

[4]  R. Kashyap.  Fiber Bragg Gratings , 1999 .

[5]  Eric Udd,et al.  Acoustic emission detection using fiber Bragg gratings , 2001, SPIE Smart Structures and Materials + Nondestructive Evaluation and Health Monitoring.

[6]  A. Minardo,et al.  Response of fiber Bragg gratings to longitudinal ultrasonic waves , 2005, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[7]  Don Becker,et al.  Balanced photoreceivers for analog and digital fiber optic communications (Invited Paper) , 2005, SPIE Defense + Commercial Sensing.

[8]  David E McClelland,et al.  Laser frequency-noise-limited ultrahigh resolution remote fiber sensing. , 2006, Optics express.

[9]  Graham Wild,et al.  A transmit reflect detection system for fiber Bragg grating photonic sensors , 2007, SPIE Micro + Nano Materials, Devices, and Applications.

[10]  G. Wild,et al.  Acousto-Ultrasonic Optical Fiber Sensors: Overview and State-of-the-Art , 2008, IEEE Sensors Journal.

[11]  P. Laporta,et al.  Fiber strain sensor based on a pi-phase-shifted Bragg grating and the Pound-Drever-Hall technique. , 2008, Optics express.

[12]  Hiroshi Tsuda,et al.  Ultrasonic Sensitivity of Strain-Insensitive Fiber Bragg Grating Sensors and Evaluation of Ultrasound-Induced Strain , 2010, Sensors.

[13]  Mamoru Shimazaki,et al.  Delamination detection in composite laminates using dispersion change based on mode conversion of Lamb waves , 2010 .

[14]  Vasilis Ntziachristos,et al.  High-sensitivity compact ultrasonic detector based on a pi-phase-shifted fiber Bragg grating. , 2011, Optics letters.

[15]  X. Gu,et al.  Musical instrument pickup based on a laser locked to an optical fiber resonator. , 2011, Optics express.

[16]  Yoji Okabe,et al.  Ultrasonic sensor employing two cascaded phase-shifted fiber Bragg gratings suitable for multiplexing. , 2012, Optics letters.

[17]  Vasilis Ntziachristos,et al.  Wideband optical sensing using pulse interferometry. , 2012, Optics express.