Design and Performance Analysis of Fiber Bragg Grating based Temperature Sensor

Abstract

In this paper, we demonstrate the design of an fiber Bragg gratings (FBG) based temperature sensor. The temperature sensor was simulated using finite element method. We considered circular Bragg gratings to design our temperature sensor. During simulation, the ambient temperature of the temperature sensor was varied between 0°C to 460°C. A significant amount of Bragg wavelength shift was detected due to the variation of ambient temperature of the FBG based temperature sensor. In order to investigate the impact of number of Bragg gratings on the wavelength sensitivity of the temperature sensor, we utilized both 3 and 5 Bragg gratings based FBG sensors where the Bragg gratings were engraved inside fiber core. The temperature sensor consisting 5 Bragg gratings showed better temperature sensitivity compared to the 3 Bragg gratings engraved temperature sensor. On the contrary, the 5 Bragg gratings engraved temperature sensor was able to sense temperature up to 460°C as compared to 150°C for 3 Gratings incorporated sensor. To optimize the probe distance, we examined the response time, i.e. heat transfer time of the temperature sensor by placing the probe at different locations of the radial axis of the fiber core. The lowest response time was detected when the probe was placed at a distance of 3.19 µm from the center of the fiber core. Our FBG based temperature sensor showed excellent results in sensing the ambient temperature and can be considered as a potential candidate for commercial applications.