We reviewed the tellurite glass purification studies performed over the last 20 years, in particular dealing with the mid-infrared transmission performances. Best results are obtained under rich O 2 atmosphere with platinum crucibles although Gibbs energy calculations show that other crucibles material are possible such as gold or alumina. From the point of view of the thermodynamics of involved oxidation reactions only, we identified the suitable conditions based on Gibbs energy calculations to be a synthesis temperature set above 900K and a O 2 pressure around 10 5 Pa. The performances of the different purification technics were also compared. Finally, we analyzed the tellurite fibers recently optimized for mid-infrared which present low attenuation up to 4 µm allowing supercontinuum generation up to 5 µm.

We demonstrate the fabrication of arsenic-and antimony-free chalcogenide glasses compatible with glass fiber processing. Optical fibers with distinct index profiles are presented and characterized, namely single material fibers with or without a suspended core and standard step-index fibers with varying core diameter. In addition, we evidence their potential for nonlinear photonic devices in the mid-infrared spectral region by means of supercontinuum generation experiments in the femtosecond regime. Spectral broadenings are obtained, extending on several octaves in the mid IR from 2 to 14 µm.