Infrared and Laser Engineering, Volume. 54, Issue 4, 20250045(2025)

Research on spiral winding distributed fiber optic vector acoustic sensor technology (invited)

Cunzheng FAN1, Zhengxuan SHI1, Yuran TAO1, Hanyu JIN1, Hao LI1, Zhijun YAN1,2, and Qizhen SUN1,2、*
Author Affiliations
  • 1National Engineering Research Center for Next Generation Internet Access System, College of Optoelectronic Information, Huazhong University of Science and Technology, Wuhan 430074, China
  • 2Huazhong University of Science and Technology Wuxi Research Institute, Wuxi 214174, China
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    ObjectiveCompared of conventional acoustic sensors, vector acoustic sensing technology offers more comprehensive sound field information, enhanced sound source localization capabilities, and superior monitoring accuracy. It plays a crucial role in various applications, including oil and gas exploration, perimeter security monitoring, and geophysical and oceanographic research. While vector acoustic sensing technology is currently experiencing rapid development, it faces challenges such as complex structural designs, the need for individual calibration, and high maintenance requirements, which limit its suitability for large-scale, distributed acoustic wave detection. In this paper, we present a novel approach utilizing scattering-enhanced fibers and elliptically spiral winding fiber optic cables to address the limitations of conventional fiber distributed optic acoustic sensing (DAS) technology, which is incapable of performing vector detection, and realize distributed fiber optic vector acoustic sensing.MethodsThe vector sensing mechanisms of HWC and EWC are analyzed and compared, and their directional sensitivity is also simulated and calculated (Fig.1-Fig.2). The results show that due to the non-central symmetry of EWC, it has omnidirectional sensitivity to the three directions of vector signals. Therefore, EWC is chosen as the vector sensing unit in this article, and the corresponding vector signal decoupling scheme is studied (Fig.3). Firstly, an appropriate spatial coordinate system is constructed using the different sensitivity functions of the EWC vector sensing unit to obtain the EWC sensitivity curve. The time-domain signals detected by the vector sensing unit are separated and normalized to obtain the vector spatial coordinates, which are then used to decouple the vector acoustic angle information using the minimum distance matching algorithm in the appropriate spatial coordinate system.Results and DiscussionsAn experimental setup was built to verify the sensing performance of the proposed elliptically wound cable (Fig.4). Firstly, the response linearity was tested by changing the sound pressure from 0.5 Pa to 1.5 Pa. And the R squares were all above 0.9978 (Fig.5 (a)-(c)). Next, the directional responses were measured with different φ (rotating the tube in 10° intervals). Then the incidence angles were demodulated through the algorithm mentioned in the previous section. Results show that the angular positioning can be realized with a 1° accuracy and ~3.8° RMS error. Furthermore, the acoustic information in the x and y direction were restored with the angular positioning results above. And the errors of the sound pressure are all less than 0.15 Pa (Fig.7). In conclusion, it’s proved that the elliptically wound cable has great feasibility in three-component acoustic sensing.ConclusionsA distributed vector acoustic detection method based on spiral wound optical cables was proposed, which meet the demand for distributed vector acoustic wave detection. By changing the fiber winding angle, multiple sets of acoustic data were obtained. Based on the directional response of different winding angle fiber, directional decoupling was used to achieve vector acoustic detection. The spiral winding structure with triple winding angle fiber was tested and verified, and the results showed that the scheme achieved vector acoustic wave detection in a two-dimensional plane, with a root mean square error of 3.8° in detection direction and a signal amplitude error of less than 0.15 Pa.

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    Cunzheng FAN, Zhengxuan SHI, Yuran TAO, Hanyu JIN, Hao LI, Zhijun YAN, Qizhen SUN. Research on spiral winding distributed fiber optic vector acoustic sensor technology (invited)[J]. Infrared and Laser Engineering, 2025, 54(4): 20250045

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    Paper Information

    Category: Invited research article

    Received: Jan. 15, 2025

    Accepted: --

    Published Online: May. 16, 2025

    The Author Email: Qizhen SUN (qzsun@mail.hust.edu.cn)

    DOI:10.3788/IRLA20250045

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