[1] [1] WU R J, ZHENG B L, HE P F. Influence of encapsulation structures for embedded fiber-optic Bragg grating sensors on strain measurement ［J］. Opt. Precision Eng., 2014, 22(1): 24-30. (in Chinese)

[2] [2] TANG B, HUANG J B, GU H C. Research progress of fiber grating hydrophone probe encapsulation technology ［J］. Optical Communication Technology, 2017(1): 45-48. (in Chinese)

[3] [3] SAI Y ZH, JIANG M SH, SUI Q M, et al.. Acoustic emission location based on FBG array and MVDR algorithm ［J］. Opt. Precision Eng., 2015, 23(11): 3012-3017. (in Chinese)

[4] [4] VILLALBA S, CASAS J R. Application of optical fiber distributed sensing to health monitoring of concrete structures ［J］. Mechanical Systems and Signal Processing, 2013, 39(1-2): 441-451.

[5] [5] CAO Y L, YANG F, XU D, et al.. Disturbed fiber vibration sensor based on 3×3 Michelson interferometer ［J］. Chinese Journal of Lasers, 2016, 43(10): 1010001. (in Chinese)

[6] [6] WEI P, SHAN X K, SUN X H. Frequency response of distributed fiber-optic vibration sensor based on nonbalanced Mach-Zehnder interferometer ［J］. Optical Fiber Technology, 2013, 19(1): 47-51.

[7] [7] WADA K, NARUI H, YAMAMOTO D, et al.. Balanced polarization maintaining fiber Sagnac interferometer vibration sensor ［J］. Optics Express, 2011, 19(22): 21467-21474.

[8] [8] RUSSELL S J, BRADY K R C, DAKIN J P. Real-time location of multiple time-varying strain disturbances, acting over a 40-km fiber section, using a novel dual-Sagnac interferometer［J］. Journal of Lightwave Technology, 2001, 19(2): 205-213.

[9] [9] KONDRAT M, SZUSTAKOWSKI M, PAKA N, et al.. A Sagnac-Michelson fibre optic interferometer: signal processing for disturbance localization ［J］. Opto-Electronics Review, 2007, 15(3): 127-132.

[10] [10] BAO X Y, CHEN L. Recent progress in distributed fiber optic sensors ［J］. Sensors, 2012, 12(7): 8601-8639.

[11] [11] ZHANG C X, ZHONG X, LI L J, et al.. Long-distance intrusion sensor based on phase sensitivity optical time domain reflectometry ［J］. Infrared and Laser Engineering, 2015, 44(2): 742-746.

[12] [12] DING X X, ZHANG X, WANG H B, et al.. Influences of modulation frequency on dynamic performance of vibration sensor based on Φ-OTDR ［J］. Infrared and Laser Engineering, 2015, 44(1): 210-214.

[13] [13] HUI X N, ZHENG S L, ZHOU J H, et al.. Electro-optic modulator feedback control in phase-sensitive optical time-domain reflectometer distributed sensor ［J］. Applied Optics, 2013, 52(35): 8581-8585.

[14] [14] PENG F, WU H, JIA X H, et al.. Ultra-long high-sensitivity Φ-OTDR for high spatial resolution intrusion detection of pipelines ［J］. Optics Express, 2014, 22(11): 13804-13810.

[15] [15] KOYAMADA Y, IMAHAMA M, KUBOTA K, et al.. Fiber-optic distributed strain and temperature sensing with very high measurand resolution over long range using coherent OTDR［J］. Journal of Lightwave Technology, 2009, 27(9): 1142-1146.

[16] [16] NAKAZAWA M. Rayleigh backscattering theory for single-mode optical fibers ［J］. Journal of the Optical Society of America, 1983, 73(9): 1175-1180.

[17] [17] JUKAITIS R, MAMEDOV A M, POTAPOV V T, et al.. Interferometry with Rayleigh backscattering in a single-mode optical fiber ［J］. Optics Letters, 1994, 19(3): 225-227.

[18] [18] SHANG Y, YANG Y H, WANG C, et al.. Optical fiber distributed acoustic sensing based on the self-interference of Rayleigh backscattering ［J］. Measurement, 2016, 79: 222-227.

[19] [19] SHANG Y, YANG Y H, WANG C, et al.. Study on demodulated signal distribution and acoustic pressure phase sensitivity of a self-interfered distributed acoustic sensing system ［J］. Measurement Science and Technology, 2016, 27(6): 065201.

[20] [20] ZENG ZH M, LIU F, FENG H, et al.. Digitalized demodulation based on 3×3 coupler for dual Mach-Zehnder fiber interferometer ［J］. Opt. Precision Eng., 2014, 22(6): 1410-1417. (in Chinese)