Dynamic strain measurements on a cantilever beam using stimulated Brillouin scattering

Stimulated Brillouin scattering in a single-mode optical fiber was employed to measure the vibratory strain in a 3.7 m long cantilever beam. The measurements were carried out using a configuration based on the use of two counter-propagating optical pulses. Comparison between the experimental results and a numerical analysis based on a finite-element method demonstrated that the measurement technique could be used to detect the dynamic strain, as well as permitting one to analyze the effect of the limited spatial resolution of the sensor on the mode shape reconstruction accuracy. S Online supplementary data available from stacks.