High sensitivity vector torsion sensor based on a single Stress-Applying fiber Sagnac interferometer

• Published in: Optical fiber technology Vol. 80; p. 103431
• Main Authors: Cao, Jiaqi, Lou, Shuqin, Huang, Bingsen, Gu, Shuai, Jia, Haoqiang, Sheng, Xinzhi, Wang, Xin
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.10.2023
• Subjects: Direction recognition; Sagnac interferometer; Single Stress-Applying Fiber (SSAF); Torsion angle sensor; Torsion angle sensor; Single Stress-Applying Fiber (SSAF); Sagnac interferometer; Direction recognition
• ISSN: 1068-5200; 1095-9912
• DOI: 10.1016/j.yofte.2023.103431

•A torsion sensor based on a Single Stress-Applying Fiber (SSAF) Sagnac interferometer isproposed and experimentally demonstrated.•The sensor can achieve themeasurement sensitivity up to 53.3 nm/(rad/m)and has directional recognition characteristics.•The influence offiber structure on sensorperformanceis analyzed theoretically. A vector torsion sensor based on a Single Stress-Applying Fiber (SSAF) Sagnac interferometer is proposed and experimentally demonstrated. Taking use of the high birefringence and structural asymmetry of the SSAF, the spectrum of SSAF based Sagnac interferometer shows both wavelength shift and intensity variation with the change of torsion angle. A torsion sensitivity as high as 53.3 nm/(rad/m) can be achieved by wavelength demodulation and 4.3 dB/(rad/m) by intensity demodulation. In addition, the torsion direction can be also recognized in the torsion angle range from −50° to 50°. The temperature cross sensitivity is 0.03 rad/m/℃ by wavelength demodulation in the temperature range from 20℃ to 38℃. The advantages of high sensitivity, direction recognition, multi-parameter demodulation and simple structure make the sensor great potential in civil engineering, surgical robot and other applications.