A highly sensitive photonic crystal fiber temperature sensor based on Sagnac interferometer with full liquid filling

• Published in: Optical and quantum electronics 2023-04, Vol.55 (4), Article 371
• Main Authors: Zhang, Yinping, Zhang, Xiuqing, Chu, Shichao, Fan, Zhenkai
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Computer Communication Networks; Crystal fibers; Electrical Engineering; Finite element method; Interferometers; Lasers; Optical Devices; Optics; Photonic crystals; Photonics; Physics; Physics and Astronomy; Sensitivity; Temperature sensors
• ISSN: 0306-8919; 1572-817X
• DOI: 10.1007/s11082-023-04669-0

A highly sensitive photonic crystal fiber temperature sensor based on Sagnac interferometer with full liquid filling is proposed. All of the air holes in the PCF are filled with temperature-sensitive liquid, the structure is analyzed theoretically and numerically using the finite element method. Since the sensitivity is related to the group birefringent grating, the size of the sensitivity can be reflected by comparing the absolute value of the group birefringent grating. The structure is optimized by modifying the diameter of d 0 , d 1 and d 2 of the air holes for the photonic crystal fiber. In the process of numerical calculation, the best parameters are selected by comparing the absolute value of the group birefringent grating near the special wavelength to obtain higher sensitivity. The average sensitivity of 35.14 nm/°C and − 27.71 nm/°C are obtained at 27–32 °C in a parametrically optimized structure and R 2 are 0.98455 and 0.9779. The RI sensitivity is also studied as RI changes from 1.404 to 1.409, the average sensitivity are − 53,714 nm/RIU and − 47,714.29 nm/RIU.