Phase Reconstruction for the Frequency Response Measurement of FBGs

A signal processing algorithm is applied to optical spectral analyzer measurements in order to reconstruct phase response of FBGs from easy-to-obtain module data, so avoiding the use of costly and complex equipment for direct measurement of frequency response. In order to prove validity, reconstructed phase, both in transmission and reflection, is then compared to measures from three different techniques (interferometric, modulation phase-shift, and single-sideband modulation).