Numerical Modeling to evaluate the performance of FBG-based Strain Sensors

Fiber Bragg Gratings (FBGs) result in an optical fiber due to the variation of the refractive index in the core material. Sensors based on FBG accumulate the advantages of optical fiber such as immunity to electromagnetic interference, compact size and lightweight, suitability for remote monitoring, flexibility, and multiplexing capabilities. Recently, FBG based strain sensors attain intense research interest due to their high sensitivity and comparatively lower cost. These sensors work with simple principle; Bragg wavelength shifts when strain is induced on the fiber. In this paper, we aim to design a FBG based strain sensor and then numerically modeled it in COMSOL environment to investigate the sensor performance. To design the system, we incorporate a solid mechanical model to the FBG model in Radio Frequency module to apply external force to produce stain in the FBG. Finally the results from the numerical model is compared with the existing analytical model, which shows good agreement.