Highly Sensitive FBG-Based Sensor for Temperature Measurement Operating in Optical Fiber

The temperature sensors are remarkably required for highly sensitive temperature monitoring in advanced applications including nanobiosensing, healthcare, disease diagnosis, and so on. Therefore, this paper presents a fiber Bragg gating (FBG)–based sensor designed for demanding novel applications, such as temperature measurements in biotechnology. We propose a highly sensitive temperature sensor in the near-infrared range made from germanium-doped silica core optical fiber, which provides high-performance properties. To evaluate the structure, several practical parameters are considered including environmental temperature variations. The structure first is numerically simulated by the finite difference time domain method. Then, by using the PSO algorithm, appropriated results are obtained. Finally, a fabricated structure is presented. It is demonstrated that the sensitivity of the transmitted light can be tuned through temperature variations of FBG. Moreover, the effects of alteration of FBG period on the sensitivity have been analyzed. Results show that the sensitivity of the proposed temperature sensor can be controlled by tuning the temperature. In the optimum design of the proposed FBG-based temperature sensor, the maximum value of sensitivity is achieved as high as S = 717 1/°C as temperature change from 0 to 140 °C. This work may have significant prospects in tunable, highly sensitive temperature sensors in optical biotechnology.