@article{TANG2026, 
author = {Rong TANG and Sijin ZHENG and Yunhe SONG and Zhikai LIU and Tianyu HUA and Shengtao ZOU and Qiang JING and Yunjiang RAO},
title = {Ultra-Long Ultra-Broadband Distributed Acoustic Sensing With Zadoff-Chu Nonlinear Frequency Modulation and LEAF},
year = {2026},
journal = {Photonic Sensors},
volume = {16},
number = {1},
pages = {9560009},
keywords = {Optical fiber sensing, distributed acoustic sensing, nonlinear frequency modulation},
url = {https://www.sciopen.com/article/10.26599/PhoS.2026.9560009},
doi = {10.26599/PhoS.2026.9560009},
abstract = {The performances of fiber-optic distributed acoustic sensing (DAS) systems are fundamentally limited by the trade-off between the sensing distance and response bandwidth (RB), constraining the effectiveness of the DAS for long-haul sensing applications greatly. To break such a limitation, this paper proposes a novel Zadoff-Chu (ZC) based nonlinear frequency modulation (ZC-NLFM) scheme that combines the zero-correlation property of the ZC method with the chirp diversity of NLFM. The generated ZC-NLFM pulses exhibit excellent sidelobe and inter-pulse interference suppression, enabling high-sensitivity DAS demodulation even under low signal-to-noise ratio conditions. Furthermore, by employing the large-effective-area fiber (LEAF) with the lower attenuation, higher stimulated Brillouin scattering threshold, and Raman amplification, a wide-frequency-range, long-distance, and low-noise DAS (WLL-DAS) with high strain sensitivity of 94.34                     p                                                  ε                                              /                                                                                                  p                                                                                                                                      ε                                                                                                                                                        Hz                                                                                                                                                Hz                     over a wide RB of up to 7 kHz and an ultralong sensing distance of 148 km at the spatial resolution of 10 m is achieved simultaneously. Compared to the conventional DAS, the proposed WLL-DAS achieves a 22-fold increase in the RB over an ultralong distance of >140 km, significantly extending the performance boundary and application range of the DAS.}
}