Method for Enhancing and Controlling Temperature Sensitivity of Fiber Bragg Grating Sensor Based on Two Bimetallic Strips

This paper presents a novel structure based on bimetallic strips for enhancing temperature sensitivity of fiber Bragg grating (FBG) sensors. Two different types of sensor heads have been designed for this implementation. The first sensor head consists of an FBG that is fixed between ceramic block on one side and a bimetallic strip made up of aluminum and copper on the other. The second sensor head consists of an FBG that is fixed between two bimetallic strips. Theoretical and experimental studies carried out on these proposed sensor heads resulted in an increase in temperature sensitivity of about six times greater than that of bare FBG sensor. Further, the proposed sensors have shown good linearity and stability.