Nanoparticles in optical fibers: the good, the bad and the ugly of light scattering
Résumé
Since the 1970s, the development of optical fibers has been relying on the quest for the perfect silica glass, i.e. the most transparent one. Meanwhile, silica glass introduces limitations (high phonon energy, low rare-earth ions solubility, etc.) which could be detrimental for new applications. To overcome those drawbacks, a recent strategy consists of embedding nanoparticles in the core of the optical fiber [1]. For instance, such waveguides would combine the advantages of silica (transparency, cost, chemical and mechanical durability, etc.) and the specific properties provided by the
nanoparticles encapsulating the rare-earth ions. However, nanoparticles induce light scattering. Then, it has been required to prepare the smallest nanoparticles to avoid light scattering. Despite the promising interest for such fibers, scarce results have been published over the last 20 years. During this presentation, we discuss the process to prepare optical fibers containing nanoparticles. In particular, we will focus on the chemical composition of nanoparticles demonstrating that we need to reconsider the doxa ”the smaller, the better” [2]. We also present some results taking advantage of light scattering to promote new fiber sensors specifically dedicated to medical applications [3]. All
these results demonstrate the great potential of nanoparticles containing optical fibers.