Distributed fiber-optic frequency-domain Brillouin sensing

The experimental validation of a full frequency-domain fiber-optic Brillouin sensing technique for temperature/strain measurements is presented. An original formulation is employed which relates the frequency-domain measurements to the Brillouin gain profile along the sensing fiber, useful to both improve the signal-to-noise ratio and to cope with the non-local effects occurring when long measurement distances are involved. By this formulation, a reconstruction algorithm is derived which determines the temperature/strain profile that provides a best fit to the measured data. Preliminary experimental results confirm the validity of the proposed technique.