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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 polarization‐independent refractive index (RI) sensor with a sensitivity of 50 nm/RIU is demonstrated. The proposed RI sensor simply consists of a liquid crystal (LC) polymeric polarization grating film and one glass substrate. The wavelength shift over the RI of the surrounding medium is investigated through anisotropic rigorous coupled‐wave analysis. Such an LC‐based polarization‐independent RI sensor not only enables the usage of an unpolarized light source but also manifests a high sensitivity, offering great potential for the integration with display systems. [ABSTRACT FROM AUTHOR]

A polarization independent refractive index (RI) sensor with a RI sensitivity of 50 nm/RIU is demonstrated. The proposed RI sensor simply consists of a liquid crystal (LC) polymeric polarization grating film and one glass substrate. The wavelength shift over the refractive index of surrounding medium is investigated through anisotropic rigorous coupled‐wave analysis. Such a LC‐based polarization independent RI sensor not only enables the usage of an unpolarized light source but also manifests a high sensitivity, offering great potential for the integration with display systems. [ABSTRACT FROM AUTHOR]

In this work, environment friendly Ga‐Sb‐S‐I chalcohalide glasses and fibers are developed for mid‐infrared applications. The developed Ga8Sb32S60‐xIx (x = 0‐10) glasses have a transmission window of ~0.7‐14 µm, linear refractive indices (n0) of ~ 2.690‐2.751 at 1.55 µm, nonlinear refractive indices (n2) of ~10.5‐12.4 × 10−14 cm2/W at 1.55 µm, and zero dispersion wavelengths (λ0) of ~4.94‐5.25 µm. The developed Ga8Sb32S55I5/Ga8Sb31S56I5 (core/cladding) fiber can transmit infrared light from below 2 µm to ~8 µm, and shows the minimum loss of ~1.2 dB/m at ~6 µm. The wide transmission window, high optical nonlinearity and superior thermal stability against crystallization of the glasses, and the good 2‐8 µm transmission property of the fiber make these materials promising for mid‐infrared applications such as thermal imaging, nonlinear optics, and laser transmission. [ABSTRACT FROM AUTHOR]

In this study, a new chalcohalide glass system, Ga2S3-Sb2S3-CsI, is reported. It has a glass-forming domain composed of ~0-35 mol% Ga2S3, ~15-95 mol% Sb2S3, and ~0-55 mol% CsI. The glasses have a wide transparent window of ~0.7-13.5 μm, high third-order nonlinear refractive indices of ~1.7-8.7×10−14 cm2/W @ 1.55 μm, and relatively short zero group-velocity-dispersion wavelengths of 3.8-5.15 μm. The glasses can dissolve more than 2 mol% active ions (e.g., Dy3+), and the doped glasses show intense emissions in the mid-infrared. These superior properties demonstrate their good potentials for mid-infrared applications such as thermal imaging, nonlinear photonics and lasers. [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]