Highly sensitive temperature sensor based on sagnac interferometer using photonic crystal fiber with circular layout

• DOI: 10.1016/j.sna.2020.112236
• Publication Date: 2020-08-01T17:30:54Z
• Authors: Yundong Liu; Xili Jing; Hailiang Chen; Jianshe Li; Ying Guo; Song Zhang; Hongyu Li; Shuguang Li
• Keywords: Linearity

Abstract A temperature sensor based on Sagnac interferometer (SI) using photonic crystal fiber (PCF) with circular layout is proposed. Temperature measurement can be realized by filling the temperature sensitive liquid with high thermo-optic coefficient into the air holes. Considering the convenience of the experimental operation, three easy-to-operate liquid filling methods (FMs) were used to investigate the optical transmission characteristics of this sensor by the finite element method (FEM), the results show that two of which exhibit respective detection advantages in different aspects. One of the feasible methods is that all air holes are filled with temperature sensitive liquid. A single sensing interference dip with high detection sensitivity can be achieved, its average sensitivity reaches to 18.27 nm/°C. Another method is that only the large size air holes are filled with the temperature sensitive liquid. Two sensing interference dips with good linearity can be realized simultaneously. The linearity R2 are up to 0.99947 and 0.99877, corresponding average sensitivities are 9.47 and 8.57 nm/°C, respectively. Besides, these two proposed FMs are easier to be completed than FMs of some reported works. The proposed PCF temperature sensor with excellent detection performances, simple FMs and structural design has great application prospects to detect environmental temperature.