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Distributed fiber sensing using brillouin optical correlation domain analysis (BOCDA) up to 314 meter

In this paper, a distributed fiber sensing system based on Stimulated Brillouin scattering (SBS) effect is experimentally studied. Using Brillouin optical correlation domain analysis, the spatial resolution was affected by the reference frequency and the sideband component suppressed in the probe. The lower side band and the central wavelength was filtered by a fiber Bragg grating (FBG). We adjusted the sensitivity of the lock-in amplifier so we could read the data correctly without using a Fabry-Perot tunable filter and optimize the input signal quality. As for the modulation amplitude, it was selected from the original 100 mV unit as small as 1 mV so the modulation depth of the selection could be more accurate. We successfully achieved the measurement range 314 m with 3 m spatial resolution.