Synthesis and shaping of high IR refractive index Te-based chalcogenide glasses

Chalcogenide glasses within the Ge-Se-Te ternary system are promising candidates for mid- and long-wave infrared (MWIR and LWIR) applications due to their high refractive indices and wide transmission windows. This study explores the synthesis by the melt-quenching method, thermal stability, and optical properties of ten tellurium-rich glasses. Three compositions are then selected, Ge20Se10Te70, Ge21Se11Te68, and Ge25Se15Te60, to study the influence of the synthesis route used (melt-quenching or mechanosynthesis) on the sintering of glass powders by Spark Plasma Sintering (SPS) to form IR transparent pellets. Comprehensive characterizations including Differential Scanning Calorimetry (DSC), X-Ray Diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Transmission Electron Microscopy (TEM), and ellipsometry were performed. The impact of magnesium doping for Ge-O bond suppression and its compatibility with SPS was also evaluated. Results highlight the potential and limitations of these compositions in fabricating bulk infrared optics by mechanical milling and flash sintering.