Simultaneous measurement of curvature and temperature using a 3D-printed seven-core optical fiber inscribed with a fiber Bragg grating

This study proposes a dual-parameter sensor to simultaneously measure curvature and temperature using a 3D-printed seven-core optical fiber inscribed with a fiber Bragg grating (FBG).The seven-core fiber used was prepared by 3D-printing fiber technology of great flexibility in both structure and material.Attributed to the asymmetrical structure of this 3Dprinted fiber, the sensor is capable of distinguishing the bending directions.Furthermore, the sensing characteristics and the directional recognition mechanism of the sensor are analyzed through both theoretical simulations and experimental investigations.The proposed sensor incorporates two sensing elements, specifically the Mach-Zehnder interferometer (MZI) and FBG.The combination of the MZI and FBG in the sensor enables simultaneous measurement of curvature and temperature.This vector sensor has a sensitivity of 25.782 nm/m -1 in the curvature range of 0-1.518 m -1 , when the bending is applied along the defined direction of 30.Within the temperature range of 20.0-110.0C, the temperature sensitivity is 34 pm/C.Experimental results validate the excellent performance of the proposed sensor, providing an efficient and scalable solution for dual-parameter sensing in future industrial and environmental applications.