Enhancing the temperature sensitivity of fiber Bragg grating sensor using bimetallic strip

This paper presents theoretical and experimental results carried out on a simple structure based on bimetallic cantilever to enhance temperature sensitivity of fiber Bragg grating (FBG) sensors. Two metals of equal length and width but having different coefficients of thermal expansion (CTE) are bonded with electric arc welding to form the bimetallic strip and FBG was longitudinally affixed to that metallic strip having larger coefficient of thermal expansion. It was observed that the temperature sensitivity of the proposed FBG sensor has increased 5 times more compared to the bare FBG sensor. Moreover, the proposed sensor showed excellent linearity, reversibility, and repeatability.