Abstract

A high dynamic range distributed acoustic sensing (DAS) system is demonstrated based on a dual-wavelength ($2\lambda$) interferometric acoustic sensor array, constructed using $2\lambda$ fiber Bragg grating pairs (FBGPs). Each FBGP is composed of two weak FBGs presenting ${-}30$-dB reflectivity and center wavelengths of 1535 nm and 1565 nm. With the phase demodulation results from the two wavelengths, $2\lambda$ linear regression phase unwrapping is implemented, which significantly enhances the dynamic range of the DAS system. By examining the four time-division-multiplexed sensors, an average background noise level of ${-}105.2\;{\rm{dB rad/}}\sqrt {{\rm{Hz}}}$ at 1 kHz and a cross talk level lower than ${-}70\;{\rm{dB}}$ at 1 kHz are achieved.

© 2021 Optical Society of America

High sensitivity and large measurable range distributed acoustic sensing with Rayleigh-enhanced fiber

Ji Xiong, Zinan Wang, Jialin Jiang, Bing Han, and Yunjiang Rao
Opt. Lett. 46(11) 2569-2572 (2021)

152 km-range single-ended distributed acoustic sensor based on inline optical amplification and a micromachined enhanced-backscattering fiber

Ali Masoudi, Martynas Beresna, and Gilberto Brambilla
Opt. Lett. 46(3) 552-555 (2021)

Heterodyne detection applied to a fiber Bragg grating-based sensor using a directly modulated distributed feedback laser

Keiji Kuroda
Opt. Lett. 46(16) 3985-3988 (2021)

Large dynamic-range fiber Bragg grating sensor system for acoustic emission detection

Zhe Gong, Jiawei Che, Heming Wei, and Sridhar Krishnaswamy
Appl. Opt. 60(19) 5547-5552 (2021)

Quasi-distributed fiber-optic acoustic sensing system based on pulse compression technique and phase-noise compensation

Mengshi Wu, Xinyu Fan, Qingwen Liu, and Zuyuan He
Opt. Lett. 44(24) 5969-5972 (2019)