Frequency-domain analysis of dynamically applied strain using sweep-free Brillouin time-domain analyzer

Fast reconstruction of the whole Brillouin gain spectrum is experimentally demonstrated, using sweep-free Brillouin optical time-domain analysis (SF-BOTDA). Strain variations with frequencies up to 400Hz are spectrally analyzed, achieving strain sensitivity of 1microstrain per root Hz at a sampling rate of 5.5KHz and a spatial resolution of 4m.