Distributed OTDR-interferometric sensing network with identical ultra-weak fiber Bragg gratings.

We demonstrate a distributed sensing network with 500 identical ultra-weak fiber Bragg gratings (uwFBGs) in an equal separation of 2m using balanced Michelson interferometer of the phase sensitive optical time domain reflectometry (φ-OTDR) for acoustic measurement. Phase, amplitude, frequency response and location information can be directly obtained at the same time by using the passive 3 × 3 coupler demodulation. Lab experiments on detecting sound waves in water tank are carried out. The results show that this system can well demodulate distributed acoustic signal with the pressure detection limit of 0.122Pa and achieve an acoustic phase sensitivity of around -158dB (re rad/μPa) with a relatively flat frequency response between 450Hz to 600Hz.

[1]  Xiaoyi Bao,et al.  Distributed Vibration Sensor Based on Coherent Detection of Phase-OTDR , 2010, Journal of Lightwave Technology.

[2]  P. Ferraro,et al.  Fiber Bragg-grating strain sensor interrogation using laser radio-frequency modulation. , 2005, Optics express.

[3]  Minghong Yang,et al.  A time- and wavelength-division multiplexing sensor network with ultra-weak fiber Bragg gratings. , 2013, Optics express.

[4]  Y. Koyamada,et al.  Fiber-Optic Distributed Strain and Temperature Sensing With Very High Measurand Resolution Over Long Range Using Coherent OTDR , 2009, Journal of Lightwave Technology.

[5]  Chang-Seok Kim,et al.  Multi-point interrogation of FBG sensors using cascaded flexible wavelength-division Sagnac loop filters. , 2006, Optics express.

[6]  Gang-Ding Peng,et al.  Distributed acoustic mapping based on interferometry of phase optical time-domain reflectometry , 2015 .

[7]  I. Bennion,et al.  Ultrasonic hydrophone based on short in-fiber bragg gratings. , 1998, Applied optics.

[8]  Michael D. Todd,et al.  Improved, operationally-passive interferometric demodulation method using 3/spl times/3 coupler , 2002 .

[9]  Yoshimura,et al.  Development of an optical fiber hydrophone with fiber Bragg grating , 2000, Ultrasonics.

[10]  Yu Zheng,et al.  On-line writing identical and weak fiber Bragg grating arrays , 2013 .

[11]  J. Juarez,et al.  Distributed fiber-optic intrusion sensor system , 2005, Journal of Lightwave Technology.

[12]  Wei Jin.  Multiplexed FBG sensors and their applications , 1999, International Symposium on Photonics and Applications.

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

[14]  Jinping Ou,et al.  Optic fiber Bragg grating based sensing technologies and their applications in structural health monitoring , 2007, Fundamental Problems of Optoelectronics and Microelectronics.

[15]  C. C. Chan,et al.  Intrinsic crosstalk analysis of a serial TDM FGB sensor array by using a tunable laser , 2000, LEOS 2000. 2000 IEEE Annual Meeting Conference Proceedings. 13th Annual Meeting. IEEE Lasers and Electro-Optics Society 2000 Annual Meeting (Cat. No.00CH37080).

[16]  Juan C Juarez,et al.  Polarization discrimination in a phase-sensitive optical time-domain reflectometer intrusion-sensor system. , 2005, Optics letters.

[17]  Juan C Juarez,et al.  Field test of a distributed fiber-optic intrusion sensor system for long perimeters. , 2007, Applied optics.

[18]  Xiaoyi Bao,et al.  Time-division multiplexing-based BOTDA over 100 km sensing length. , 2011, Optics letters.

[19]  Bo Dong,et al.  A Large Serial Time-Division Multiplexed Fiber Bragg Grating Sensor Network , 2012, Journal of Lightwave Technology.

[20]  Xiaoyi Bao,et al.  Modulated pulses based distributed vibration sensing with high frequency response and spatial resolution. , 2013, Optics express.