BOCDA fiber optic distributed strain sensing system with a polarization diversity scheme for enlargement of measurement range

We have developed Brillouin Optical Correlation Domain Analysis (BOCDA) for distributed strain measurement. BOCDA can achieve distributed strain measurement by controlling a correlation between pump and probe lightwave, with excellent spatial resolution and sampling rate compared with conventional pulse-based techniques. In this paper, we propose a scheme for polarization diversity to reduce data fluctuation by polarization state change of pump and probe lightwave in order to realize enlargement of measurement range. Stable distributed strain measurement is demonstrated along a 50m measurement range.