Development of new tellurite fibers for mid-IR applications

This paper discusses the tellurite fibers for mid-IR applications. Over the past few years, the authors have developed a glass and fiber infrastructure and have demonstrated their capability to synthesize and characterize glasses, fabricate preforms and draw fibers, and demonstrate various optical effects in these. However, the originality of this approach rests in carrying out targeted scientific studies at each step of the elaboration process, not only to solve a particular technical problem but also deepen our understanding, optimize existing solutions or discover new ones. Initially, the focus is mostly on the canonical composition of tellurite glasses, 75%TeO₂-20%ZnO-5%Na₂O (TZN75) and a variation of it, 80%TeO₂-10%ZnO-10%Na₂O(TZN80) which has certain practical advantages such as a better thermal stability. The authors also worked with modified tellurite glasses with tungsten or bismuth and have also attempted to make oxy-chalcogenide glasses with sulfur or selenium. These glasses are characterized macroscopically by X-ray diffraction and differential scanning calorimetry (DSC) and microscopically by Raman and X-ray Photo-Electron Spectroscopy (XPS). The optical properties are also determined (linear and nonlinear refractive index or third order susceptibility, transmissivity). Core-clad canes are made either by suction or built-in casting, inserted in a tube and drawn into fibers.