Nice-DREAM

This project aims to develop an original optical fibre amplifier, for photonic applications based on the encapsulation of luminescent ions in dielectric nanoparticles (DNP). It relates in particular to the study of changes of DNP during the drawing step, a key step which is a technological barrier for the development of these new fibres. The optical fibre market is currently growing in areas such as telecommunications, machining, medicine, and sensors. This expansion is underpinned by silica fibre (SiO2) glass which has many mechanical and economic advantages over alternative hosts. Nevertheless, optical amplifiers based on this glass are limited to a relatively few narrow bands in the near-infrared. The development of new applications based on optical fibres requires rethinking the nature and structure of silica-based fibre cores to achieve “augmented” amplification properties. The encapsulation of luminescent ions in DNP in principle allows control of the environment, and the engineering, of spectroscopic properties. New optical fibres are developed according to this principle. They can combine the optical and mechanical advantages of silica and provide spectroscopic properties that do not otherwise exist in this glass. The most promising route to a new family of optical fibres is based on the in-situ synthesis of DNP during the manufacture of the preform. There are several methods to prepare a preform; however they all share the drawing step, requiring extreme conditions of temperature and mechanical constraint. An 125-µm optical fibre is obtained by drawing a preform (diameter ~1cm) at high temperature (> 2000 °C). Currently there is no model or knowledge to engineering spectroscopic properties of luminescent ions doped DNP in these conditions. The fate of DNP during the drawing step is therefore the major question to elucidate for the development of such optical fibres. In this context, our unique approach is based on the study of model samples to overcome the difficulties encountered with fibre characterization. The work is organized in four stages over 42 months: (1) preparation of glasses containing luminescent ions doped DNP, (2) study of DNP properties at high temperature, (3) study of the elongation at high temperature and (4) demonstrate an application proof of concept. The experiments will be based on theoretical modelling and molecular dynamics simulations. The main objective is to determine the transfer function of the drawing step, i.e. to determine the characteristics of the nanoparticles in the preform to obtain the desired properties in the fibre. With this aim in mind, we have assembled a consortium with expertise in the fields of glass-ceramics, optical fibres, nanomaterials, phase separation in silicate materials, and thermodynamics. This proposal brings together four academic research institutes, known as top-ranked groups in their respective domains. Their global scientific and technological proficiency now spreads over various fields dealing with materials, with already initiated collaborations in these domains : materials fabrication and characterization, optics, physical-chemistry, spectroscopy, and numerical simulations. Founded on mature multidisciplinary experimental techniques, the project will cultivate the production and analysis of a large set of samples and data of primary importance in understanding DNP production in silica based optical fibre. The outcome from which will be a notable increase of the basic scientific knowledge in this photonic materials field, whereas the technological findings should have a large impact, particularly in Key Enabling Technologies such as photonics, nanotechnology, advanced materials and advanced manufacturing systems.