光学精密工程2017，Vol.25Issue(9)：2317-2323,7.DOI:10.3788/OPE.20172509.2317
空间差分干涉的光纤分布式水下声波测量
Measurement of underwater acoustic wave using optical distributed acoustic sensing based on space difference
摘要
Abstract
To detect weak underwater acoustic signal over large areas ,an optical Distributed Acoustic Sensing(DAS) scheme based on space difference of Rayleigh backscattering was presented .In this scheme ,Rayleigh backscattered light with phase changes induced by the acoustic signal along a single-mode sensing fiber was split and fed into an imbalanced Michelson interferometer .Adjusting the path difference of the imbalanced Michelson interferometer ,the Rayleigh backscattered light interference of different lengths of adjacent space segments along the sensing fiber was realized .Subsequently ,the phase information including the acoustic signal was demodulated by the 3 × 3 coupler demodulation technology .An underwater acoustic wave measuring system based on DAS was implemented ,which can not only locate the two acoustic positions accurately in real time ,but also restore the amplitude ,frequency and phase of sound waves .In addition ,the acoustic phase sensitivity is -148 .8 dB (re rad/μPa) at 1 kHz ,and the frequency response flatness at frequencies ranging from 100 Hz to 1500 Hz is within 1 .2 dB .The experimental results confirm that the novel Φ-OTDR technology can enable quantitative measurements of multiple acoustic information in real time .关键词
光纤传感/后向瑞利散射/空间差分干涉/非平衡迈克尔逊干涉仪/声压相位灵敏度Key words
optical fiber sensing/Rayleigh backscattering/space difference/imbalanced Michelson interferometer/acoustic phase sensitivity分类
信息技术与安全科学引用本文复制引用
董杰..空间差分干涉的光纤分布式水下声波测量[J].光学精密工程,2017,25(9):2317-2323,7.基金项目
山东省科技发展计划资助项目(No.2015GSF120001) （No.2015GSF120001）
山东省高校科技计划资助项目(No.J12LN15) （No.J12LN15）
山青院重点课题资助项目(No.2015ZD08) （No.2015ZD08）
