A Correlation-Based Continuous-Wave technique for measuring distributed dynamic strain along an optical fiber using Brillouin scattering

Abstract

Conventional Brillouin based strain sensors, whilst advantages over FBG-based sensors for structural monitoring applications, have low spatial resolution and are inadequate for dynamic strain measurements due to their large measurement lengths of several minutes. We present a correlation-based continuous-wave technique for high spatial resolution and distributed dynamic strain measurements. Using our technique, we have successfully measured dynamic strain from a 5cm vibrating section, at a sampling rate of 18.4Hz, and having strain accuracy of about 45.2με.