Multipath distributed acoustic sensing system based on phase-sensitive optical time-domain reflectometry with frequency division multiplexing technique

Kun Zhu, Bin Zhou, Huan Wu, Chao Shang, Linyue Lu, Muhammad Adeel, Yaxi Yan, Zhiyong Zhao, Hwa Yaw Tam, Chao Lu

Research output: Journal article publicationJournal articleAcademic researchpeer-review

8 Citations (Scopus)


We propose a multipath distributed acoustic sensing (MP-DAS) system based on phase-sensitive optical time-domain reflectometry (Φ-OTDR) and frequency division multiplexing (FDM) technique. With FDM introduced to Φ-OTDR, simultaneously monitoring of multipath vibration is realized with flexible functionality. In the proposed MP-DAS system, the parameters of each path can be adjusted individually according to the path's specific monitoring requirement. A dual path Φ-OTDR system with 1 km and 22 km measurement distance is demonstrated in the experiment. Through heterodyne detection and FDM technique, both amplitude and phase information are obtained for event locating and vibration sensing in each of the two paths, with a spatial resolution of 5 m and 10 m respectively. With changing optical power and pulse width of one path, its influence on the other path is discussed and analyzed. This proposed MP-DSA system based on FDM technique provides an efficient and cost-effective way for upgrading a conventional single DAS into an integrated DAS network, which shows great potential in many applications such as modern city civil structure monitoring with different demands.

Original languageEnglish
Article number106593
JournalOptics and Lasers in Engineering
Publication statusPublished - Jul 2021


  • Coherent detection
  • Distributed acoustic sensing
  • Distributed optical fibre sensor
  • Frequency division multiplexing
  • Phase-sensitive OTDR

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Mechanical Engineering
  • Electrical and Electronic Engineering

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