Highly Sensitive Curvature and Temperature Sensor Based on Double Groove Structure and Hollow Core Fiber

In this paper, we propose a curvature and temperature sensor based on two symmetrical grooves and a hollow core fiber (HCF) filled with polydimethylsiloxane (PDMS). The two grooves are produced by splicing both ends of the polished HCF with two multimode fibers (MMFs). The proposed groove structure is sensitive to curvature, and the PDMS, with a high thermo-optical coefficient, makes the sensor highly sensitive to temperature. The experimental results show that the sensor exhibits a high sensitivity of-6.833 nm/m-1 in the curvature range of 0 m-1 to 45.97m-1, and a high sensitivity of 4.278 nm/°C in the temperature range of 25°C to 95°C. The proposed sensor can monitor curvature and temperature simultaneously in real-time, and has potential application prospects in industrial production, biomedicine, structural health monitoring, and other fields.