Performance analysis of peak tracking techniques for fiber Bragg grating interrogation systems

in this paper, we propose a spectral correlation-based technique for tracking the wavelength shift of a fiber bragg grating. we compared this approach, by means of a monte carlo numerical simulation, to the typical peak tracking techniques applied in classic interrogation systems. as result, we obtained a considerable gain in terms of noise tolerance (about 20 db), which can be further incremented by selecting large-bandwidth gratings. this permits to increase the power budget of a fiber bragg grating interrogator without changing the optical layout, overcoming classical limitations of commercial and custom systems. penalties due to the non-idealities have been evaluated through the same monte carlo approach. finally, we discuss a practical application of the peak tracking techniques to a fiber bragg grating-based weight sensor, in which we applied the spectral correlation to track both the bragg wavelength position, spectral deformations due to high strain, and spectral non-linearity.