Research on the sampling strategy for measuring the dispersion of chirped fiber bragg grating

Sampling strategy for characterizing the group delay of chirped fiber Bragg gratings (CFBG) through fiber low coherence interferometry (LCI) is investigated. An LCI system is built to sample and record required data. The working principle is introduced and explained the functional modules of the system. The relationship among parameters of spectrum resolution, optical path difference (OPD), OPD scanning speed, data acquisition rate, data amount and so on is both qualitatively and quantitatively analyzed so as to achieve a sound parameter setting and to realize desired measurement precision. The analysis result is applied to practical experiments. Interferograms acquired at different parameter settings are provided for verifying the derivation and calculation. Finally, the group delay of the CFBG under test is calculated.