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Indexed by:Journal Papers

Date of Publication:2019-12-23

Journal:OPTICS EXPRESS

Included Journals:SCIE

Volume:27

Issue:26

Page Number:38191-38203

ISSN No.:1094-4087

Abstract:Flexible and stable demodulation techniques of large-scale fiber-optic Fabry-Perot (FP) acoustic sensors are highly desirable for accelerating their industrial applications. In this paper, we report a novel self-calibrating wavelength shifting interferometry (WSI) technique that enables simultaneous multi-point acoustic detection using diaphragm based fiber-optic FP acoustic sensors. A widely tunable modulated grating Y-branch (MG-Y) laser (1527 similar to 1567 nm) performs high-speed wavelength switching, introducing phase-shifts in the wavelength domain for real-time phase retrieval. The proposed self-calibrating WSI is easily extended for multiplexing FP acoustic sensors by calibrating the corresponding phase-shift step of each sensor probe. Based on a modified Hariharan 5-step phase shifting algorithm, the phase-shift step for each channel can be calibrated in real-time, making the system robust in applications involving large environmental perturbations. An all-optical multi-point acoustic detection system based on WSI is proposed and experimentally demonstrated for the first time. Sound source localization experiments show that the multi-point acoustic detection system works stably and the positioning accuracy is about 2.42 cm. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement