High refractive index IR lenses based on chalcogenide glasses molded by spark plasma sintering
Résumé
In this work, spark plasma sintering is used to mold non conventional chalcogenide glasses of high refractive index at low temperature (andlt;400°C). This equipment, usually used for sintering refractory materials, is presented as efficient for both densification and high precision molding of IR transparent bulks and lenses of telluride glasses. Thermo-mechanical and optical characteristics of the selected Ge25Se10Te65 glass composition were investigated showing a refractive index of 3,12@10 µm and with however a limited resistance to crystallization. Mechanical milling of raw Ge, Se, Te elements leads to a major amorphous phase with the formation of a small proportion of GeTe crystals. Remaining GeTe crystals induce a fast crystallization rate during the sintering process leading to the opacity of the material. SPS flash moldings were then performed using melt quenched glass powders to produce complex lenses. It has been found that the critical parameter to reach optimal IR transparency is mainly the powder granulometry, which should be superior to 100 µm to prevent from MIE scatterings. The possibility of producing high refractive index infrared lenses has been demonstrated even with unstable glasses against crystallization. © 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
Mots clés
Chalcogenides
Crystals
Germanium compounds
Glass
Mechanical alloying
Milling (machining)
Molding
Selenium compounds
Spark plasma sintering
Tellurium compounds
Temperature
Chalcogenide glass
Crystallization rates
Glass compositions
High refractive index
Mechanical milling
Melt-quenched glass
Optical characteristics
Powder granulometry
Refractive index
Domaines
Physique [physics]
Fichier principal
Reux-2021-High refractive index IR lenses based on chalcogenide glasses.pdf (3.73 Mo)
Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte
Commentaire : No data were generated or analyzed in the presented research.
Commentaire : No data were generated or analyzed in the presented research.