Remote fiber Bragg grating-based sensor characterization with ultra-high-resolution tunable photon counting OTDR

We report on the possibility of remotely characterizing Bragg gratings using an ultra-high-resolution tunable photon-counting OTDR. The achievable 2.8 cm resolution as well as the tunability of the technique permit the determination of the dispersion induced by the grating and its length inside the fiber. We believe that this characterization technique can be employed in long distance monitoring for different Bragg-grating fiber sensors.