Characterization of optical fibers for optimization of a Brillouin scattering based fiber optic sensor

Brillouin scattering-based distributed fiber optic sensors are powerful diagnostic and monitoring tools for structural health. Much research has been focused on improving the spatial, strain, and temperature resolutions of these systems, mainly by the use of signal processing and improved equipment. In contrast, there has been little published work on optimizing the sensor fiber itself. A number of optical fibers have been measured in order to determine how to optimize their Brillouin characteristics including the number of Brillouin peaks, the frequency of the peaks, their linewidth, the temperature and strain coefficient of each peak, and the Brillouin temperature- and strain-linewidth coefficients. Among other results, it is shown that raising the intrinsic Brillouin frequency of the fiber increases the strain and temperature coefficients of the fiber for the main Brillouin peak, which has not been previously reported.