Simulation of Fiber Bragg Grating (FBG) as A Strain Sensor

Abstract

Abstract: In this study, the Fibre Bragg grating (FBG) is modelled, simulated, and characterised with respect to maximum reflectivity, bandwidth, the impact of applied strain on the wavelength shift, λB, and the wavelength shift sensitivity with strain for an optical sensing system. This study measures the spectral response of FBG to strain using a commercial FBG with a centre wavelength of 1550 nm. The parameters employed in these simulations include the effective refractive index (1.46), the grating period (Λ) for 530 nm in the FBG performance, the variations in refractive index (∆n) from 0.0002 to 0.0020, and the fibre grating length (L) from 1 to 10 mm. The analysis of the refractive index and grating length variation yields the bandwidth and spectrum reflectivity. 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.