Distributed dynamic strain measurement using a correlation-based Brillouin sensing system

Conventional fiber Brillouin-based strain sensors are capable of distributed sensing, making them advantageous over fiber Bragg grating-based sensors for structural monitoring applications. However, Brillouin sensors have low spatial resolution and are inappropriate for dynamic strain measurements as they have large measurement times of several minutes. We present a correlation-based continuous-wave technique for high spatial resolution and distributed dynamic strain measurements using stimulated Brillouin scattering. Using our technique, we have successfully measured dynamic strain from a 5-cm vibrating section, at a sampling rate of 8.8 Hz with a strain accuracy of about /spl plusmn/38 μ/spl epsiv/.