Tellurium-Based Far-Infrared Transmitting Glasses
Abstract:Spectroscopic investigations of molecules having their main infrared (IR) signatures at longer wavelengths require optical elements transmitting lights as far as possible in the IR region toward 20 m and beyond. In this paper, several far-IR transmitting glass systems including Ge–In–Te, Ge–As–Te, as well as some compositions containing gallium, CsI, KI, or iodine are reported. Their glass-forming ability, thermal stability, and IR transmitting property are investigated. The gallium-containing glasses show intrinsic absorptions in the 15–20 m region. These absorptions disappear if gallium is replaced by indium, a heavier element, but these glasses display mediocre glass forming ability. Among the systems, Ge–As–Te glasses show superior glass-forming ability and wide IR transparency. The ΔT of glasses in this system can be as great as 145°C and most of the studied glasses exhibit excellent transparency in the 3–20 m spectral window. These glass properties compares favorably to the state-of-the-art Ge–Te–I glasses both in terms of optical quality and thermodynamic stability.
Document Type: Research Article
Affiliations: Department of Materials Science and Engineering, University of Arizona, Tucson, Arizona 85712
Publication date: 2009-12-01