Phase time delay and impulse response reconstruction from reflected power in uniform fiber Bragg gratings

One of the most important fiber-optic devices, emerged in recent years, is the fiber Bragg grating (FBG). It is essential to know the amplitude and the phase response of these FBG, in order to obtain a complete characterization of the device. The amplitude response is directly obtained from power measurements. The phase response can he obtained by interferometric techniques, based on the Michelson method. We propose, for uniform FBG, a phase, time delay, and impulse response reconstruction from power measurement. We only work with the reflected signal, though the study can be extended to the transmitted one, with special attention to the minimum-phase-shift condition.