Numerical comparison of peak detection algorithms for the response of FBG in non-homogeneous strain fields

The increasing use of Fiber Bragg Grating (FBG) in many fields, such as smart structures and structural health monitoring, requires a detailed analysis of the measured values from the optical interrogators. While the peak detection of each FBG reflection spectra is relatively simple if the strain profile is constant all over the FBG sensor, special care must be paid when the strain profile is unknown, or non-homogeneous for sure. The objective of this work is to develop a numerical model able to simulate the whole measurement process, from the strain profile to the measured peak wavelength. The numerical simulation include a T-matrix model and some of the most used peak detection algorithms. The results obtained with some of the tested strain profiles show that the measured errors can be important.