Customizing nanoparticle characteristics in Ba-rich nanoparticle-doped optical fibers to tune Rayleigh scattering

Rayleigh scattering enhanced nanoparticle-doped silica-based optical fibers have recently emerged for distributed sensing applications. To date, Ca-, Sr- and Mg-based nanoparticles have been demonstrated to be very promising for it. In this work, we add in situ growth Ba-rich nanoparticles to alkaline earth-based compositions suitable to fabricate tunable Rayleigh scattering enhanced nanoparticle-doped optical fibers. Preform fabrication conditions allow largely customizing the features of the nucleated nanoparticles in the preform core. Fiber drawing process further impact on their size and composition due to a possible reaction with the silica-based glass and allows large customization, which is translated into an optimized trade-off between Rayleigh scattering enhancement of 35.4-44.9 dB, regarding a SMF-28, and two-way optical losses, 1.2-6.9 dB/m. Sensing lengths from 6.5 to 28.7 m become possible. The possibility of easily tailoring Ba-rich nanoparticle characteristics strengthen the potential of in situ grown alkaline earth nanoparticles for future distributed optical fiber sensors.