The location accuracy in the distributed sensor based on Brillouin loss due to Brillouin slow light (Invited)

摘要

The impact of Brillouin slow light on distributed Brillouin fiber sensors is studied. We demonstrate Brillouin slow light for a 1.2 ns pulse with peak power from 3.3 to 56.2 mW at the depletion of the pump power from 1.3 mW to 83.2 mW in conventional optical fibers (SMF-28). Our experimental results show that when the depletion of the pump power is not negligible, for a given pump power the Brillouin gain and delay time of a pulse decrease when the pulse peak power increases in a long length (10 km) sensing fiber. The strong depletion of the pump beam resulting from the strong interaction between pump and probe in the fiber provides accurate local temperature and strain information at high spatial resolution. It is found that pump depletion mitigates significantly the delay: the maximum delay induced at resonance is only a fraction of the spatial resolution, which means pulse width for the spatial resolution is still valid definition when Brillouin slow light is included.