Recent progress in chalcogenide glasses applicable to infrared optical elements manufactured by molding technology

Abstract

Chalcogenide glass is a unique material applicable to infrared-transmitting optical elements that cover the atmospheric windows. It can be manufactured using molding technology, which provides mass productivity and high quality. Interest in chalcogenide glass research and developments has increased recently because of the rapid growth of the infrared optics market. This review summarizes the glass formation and properties of recently developed chalcogenide glasses. Selenium-based glasses which are widely used commercially have been introduced in comparison with infrared-transmitting crystals such as Ge and ZnSe. For sulfur-based glasses, glass-forming systems based on GeS and GaS have been described. These systems are completely free of arsenic and selenium, which are commonly used in conventional chalcogenide glasses. However, they provide glasses that are thermally stable against crystallization, and moldable. The typical spectral windows for GeS and GaS-based glasses have ranges of approximately 0.611 and 0.813 ¯m, respectively, although the short wavelength side strongly depends on the composition. Tellurium-based glasses are characterized by transmission in the far-infrared region, beyond 20 ¯m, and a refractive index higher than three. Recent studies on the temperature dependence of the viscosity and viscoelastic behaviors of chalcogenide glasses, which are both important for precision molding technology, are also discussed. Two characteristic structural relaxations have been observed in sulfide and selenide glasses.

Ensuring the Quality of the Analytical Process in a Research Laboratory

“…They possess promising properties such as transmission in middle and far infrared regions of spectra, lower values of phonon energies, and higher values of refractive indices compared to silicate glass. Determination of the density of chalcogenide materials from the GeTeIn system and the verification of analytical methods to ensure the quality and accuracy of the obtained results and their adequate interpretation is an important part of the characterizations of newly synthesized materials [16].…”

Transferability of Diffractive Structure in the Compression Molding of Chalcogenide Glass

“…Recently, thermal imaging applications are being used more frequently in various high-tech industrial fields, such as automotive, medical, security, and measurement. These applications require infrared optics, which have traditionally been made through single-point diamond turning (SPDT) using crystalline materials such as germanium, zinc selenide, zinc sulfide, and silicon, which are capable of transmitting far-infrared wavelengths [ 1 , 2 , 3 ]. These crystalline materials have proven to be effective in creating high-quality infrared optics, but the SPDT process can be expensive and is not well-suited to high volume production.…”