Application of correlation-based continuous-wave technique for fiber Brillouin sensing to measurement of strain distribution on a small size material

In this letter, we demonstrate a smart material using our technique utilizing correlation between pump-and-probe lightwaves for fiber optic distributed strain sensing with Brillouin scattering. This technique enables centimeter-order spatial resolution, which is 100 times higher than that in conventional pulsed-lightwave techniques. This letter describes verification of usefulness of the correlation-based continuous-wave technique for smart material applications. Strain distribution on the surface of a small ring is obtained with 1-cm spatial resolution.