Recent progress in Brillouin based fiber sensor technology correlation-based continuous-wave technique

Brillouin-scattering based fiber sensor technology can determine strain or temperature distribution along a fiber, and recently has been studied as promising tools for monitoring civil structures. We have recently proposed a novel technique, in which the correlation between two continuous lightwaves is controlled so as to generate the Brillouin scattering position selectively along the fiber. We have demonstrated the spatial resolution of 1 cm in this correlation-based continuous-wave technique. We have also proposed two methods for enlarging the measurement range of this technique. Additionally, we have successfully applied the technique to measure strain distribution on surface of a small ring with only 15 cm diameter. This means the technique is applicable to smart materials.