Frequency-domain analysis of dynamically applied strain using sweep-free Brillouin time-domain analyzer and sloped-assisted FBG sensing

Abstract

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