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Properties of the glasses are experimentally investigated when Ga is gradually substituted by Ge in Ga 8 Sb 32 S 60 chalcogenide glass. The glass structure is also studied to elucidate the variations of the properties. While the substitution of Ga by Ge does not remarkably change the glass transition temperature T g , the thermal stability against crystallization becomes optimum when half of the Ga atoms are replaced by Ge atoms. The short-wavelength absorption edge λ S (or optical bandgap E g ) exhibits a remarkable decrease when a small amount of Ge is added, however, its value does not change significantly with further Ga substitution. As Ga is gradually replaced by Ge, the long-wavelength cut-off edge λ L , the density ρ , the linear refractive index n , and the third-order nonlinear refractive index n 2 decrease. It is shown that the property variations of the glasses could be explained by the evolution of the glass structure. [ABSTRACT FROM AUTHOR]

Infrared graded‐index (GRIN) lenses are desirable for realizing miniaturization and lightweight of infrared imaging systems. Chalcogenide glasses have excellent infrared transparency, good rheological property, and large refractive index range, making them preferred materials for infrared GRIN lenses. In this work, aiming to find thermally matched chalcogenide compositions with high refractive index contrast for preparing GRIN glasses by the stacking diffusion approach, we investigated characteristic temperature, thermal expansion coefficient and refractive index of Ge‐As‐Se and Ge‐As‐Se‐Te glasses, optimized the glass compositions, and evaluated the feasibility of preparing GRIN glass using the optimized chalcogenide glass powders. It is found that Ge20As20Se20Te40 and Ge12As22Se66 glasses have similar softening temperature (247°C vs. 249°C), reasonably difference of thermal expansion coefficient (3.8 ppm/K), and large refractive index contrast (∼.48). The glass powders with composition xGe20As20Se20Te40‐(1‐x) Ge12As22Se66 can be hot‐pressed into glass disks with good transmittance at the same temperature and pressure. Graded refractive index profile is formed near the interface between the layers after the co‐pressed glass is thermally treated. These results demonstrate the prospect of the compositions for preparing infrared GRIN glasses. [ABSTRACT FROM AUTHOR]

A Co2+:ZnS-doped chalcogenide glass with broadband mid-infrared emission was prepared by using a hot uniaxial pressing process. The refractive index difference (Δn) between matrix glass (As 2 S 5) and crystal (Co2+:ZnS) was controlled to be 0.0042 in the emission spectral range of Co2+ to minimize the scattering effect. An ultrabroadband mid-infrared emission of 2–4 μm was observed at room temperature in the samples after excitation by using a commercially available laser diode of 1550 nm. The significant changes in the lifetime and fluorescence intensity of Co2+:ZnS-doped chalcogenide glass were measured in the temperature range of 90–290 K. A resolution of approximately 0.18 K was observed when used as a temperature detector. Furthermore, a gas-sensing device was built by using the strong and broad emissions of the sample, and the detection sensitivity of butane reached 56 ppm. These results show that this glass-ceramics can be used as optical sensing of gas and temperature. [ABSTRACT FROM AUTHOR]

In this study, a novel chalcogenide glass system, Ga-Sb-S, is reported. The glass-forming ability, the physical properties, and the structure are investigated; and the potential applications of the glasses are evaluated. The compositions consisting of ~3%-10% Ga, ~29%-37% Sb, and ~57%-63% S can form glasses. The glasses have a wide transparent window of ~0.8-14 μm, high linear refractive indices of ~2.62-2.70 (@10 μm), high third-order nonlinear refractive indices of ~12.4 × 10−14 cm2/W (@ 1.55 μm), low phonon energy, and large rare earth solubility. These favorable properties make them promising materials for mid-infrared applications such as thermal imaging, nonlinear optics, and lasers. [ABSTRACT FROM AUTHOR]