Measurement range enlargement in Brillouin optical correlation-domain reflectometry based on chirp modulation scheme

Brillouin optical correlation-domain reflectometry (BOCDR) generally suffers from the trade-off relationship between the spatial resolution and the measurement range. In this work, we perform a proof-of-concept demonstration of a chirp modulation scheme to extend the measurement range of BOCDR. In this scheme, optical frequency is modulated using a chirp-shaped waveform. We show that, although the spatial resolution is slightly deteriorated, the measurement range and the range-to-resolution ratio can be relatively largely improved. In our preliminary experiment, the range-to-resolution ratio is 471, which is approximately 3 times higher than that of a standard configuration, proving the effectiveness of this scheme.