A Study on the Simulation of Fiber Bragg Grating (FBG) as a Strain Sensor

Abstract: This study models, simulates, and characterizes the Fibre Bragg grating (FBG) in terms of maximum reflectivity, bandwidth, the effect of applied strain on the wavelength shift, λB, and the wavelength shift sensitivity with strain for an optical sensing system. This work uses a commercial FBG with a 1550 nm center wavelength to measure the spectral response of FBG to strain. The effective refractive index (1.46), the grating period (Λ) for 530 nm in the FBG performance, the fluctuations in refractive index (∆n) from 0.0002 to 0.0020, and the fiber grating length (L) from 1 to 10 mm are the parameters used in these simulations. The bandwidth and spectrum reflectivity can be obtained by analyzing the refractive index and grating length fluctuation. OriginPro Software and Microsoft Excel are used to perform simulations on the FBG. Data are generated using the Excel sheet, and visualisations are produced using OriginPro Software. The obtained results show that the bandwidth and spectral reflectivity are impacted by variations in the refractive index and grating length. Furthermore, the obtained results indicate that variations in the Bragg wavelength can be attributed to an elongation of the grating zone caused by the applied strain.