Effect of Brillouin slow light on distributed Brillouin fiber sensors

摘要

The effect of Brillouin slow light on distributed Brillouin fiber sensors (DBFSs) is studied. We demonstrate Brillouin slow light for a 1.2 ns pulse with peak powers (P_(S)) from 3.3 to 56.2 mW on depletion of the pump power (P_(P)) ranging from 1.3 to 83.2 mW in conventional optical fibers (SMF-28). Experiments show that, when pump power depletion is not negligible, for a given P_(P) the Brillouin gain and delay time of a pulse decrease when P_(S) increases in a long (>=10 km) sensing fiber. The optimum pump beam depletion resulting from strong interaction of the pump and the probe in the fiber provides accurate temperature and strain information at a high spatial resolution. Our study reveals that at low P_(P) the spatial resolution error caused by the pulse delay for a DBFS with centimeter spatial resolution is less than 5percent of the pulse length.