Seminar Announcement: Wilfried Blanc

Announcement
Wednesday, 16 April 2025, 16:00
Sala Grande Palazzina B via alla Cascata 56/C

"The hard life of nanoparticles in optical fibers"

Wilfried Blanc
Université Côte d'Azur, INPHYNI, CNRS,
France
E-mail: wilfried.blanc@univ-cotedazur.fr

Abstract
This seminar aims to introduce optical fibers containing nanoparticles in their cores. Particle-induced light scattering, an issue to design new lasers and amplifiers, has for the last seven years, on the contrary, been an opportunity to develop new applications such as fiber sensors.
Nanoparticles in optical fibers were initially introduced to obtain novel luminescence properties of rare-earth ions or transition metals ions. By encapsulating the luminescent ions within the nanoparticles, it is possible to combine the luminescence property dependent on the characteristics of the nanoparticles (composition, structure) while keeping a silica-based fiber and its advantages (e.g., low cost, reliability, numerous manufacturing processes, etc.). However, for such application, light scattering induced by the nanoparticles must be minimized, even if the ultra-low attenuation constraint can be relaxed as the targeted application for such fibers do not concern telecom fibers. From then on, it had been identified that the nanoparticles had to satisfy certain characteristics including a size of ~10 nm and a low refractive index difference between the nanoparticles and the glass host. Very recently, optical scattering induced by nanoparticles has been demonstrated to offer new opportunity, in particular to develop new fiber sensors based on the analysis of the backscattered light using Optical Backscatter Reflectometry or the comparison between transmitted and reflected intensity of light. Such sensors can be applied to measure in real time temperatures, biochemical environments, mechanical stresses then 3D deformation measurements, detection of ionizing radiation, etc.