Distributed measurement of Brillouin dynamic grating spectrum localized by an intensity- modulated correlation-domain...

Higher spatial resolution of the reflection spectrum measurement of Brillouin dynamic grating (BDG) was achieved by controlling phonon power distribution. We experimentally demonstrate the improvement effect of the light-source intensity-modulation method, proposed recently in a correlation-domain technique, and successfully detected an 8-cm cooled section in a 100-m-long polarization-maintaining fiber. Our method can improve the spatial resolution of BDG measurements, leading to high resolution discriminative and distributed fiber sensing of temperature and strain.