Mid-infrared Emission Properties Of Dy³⁺ Doped Chalcohalide Glasses

Chalcogenide glasses and halide glasses are well known as infrared optical materials,and have received considerable research interests for years.However,some immanent defects limit their practical applications.Halide glasses have low optical loss and glass transition temperatures,but poor chemical stability and high crystal izatio n tendencyChalcogenide glasses have relatively good chemical and thermal stabilities,and high glass transition temperatures which alowing high working temperature,but their mechanical properties are generally poor.To some extent,chalcohalide glass may overcome both shortcomings of the chalcogenide and halide glasses,and it can reduce the lattice or bond defects in chalcogenide glass by improving the glass technology.Based on the conventional melt-quenching method in vacuum,introduction of elemental halogen（with a low melting temperature and large polarizability）into chalcogenide glass can increase the glass packing density,avoid devitrification of the glass,and thus greatly improve their glass forming ability.A serial（100-x）Ge₂₅Sb₁₀S₆₅–xI（x=0,5,10,15,20,25 and 30 wt.%）chalcohalide glasses and ones doped with 0.1 wt.%Dy³⁺rare-earth ions were synthesized and studied.The role of iodine（I₂）in the Ge-Sb-S-I system glass and its effect on the structure,thermal and optical properties were analyzed.The physical and chemical properties of the glass were measured by XRD,optical microscope,differential scanning calorimetr y and so on.The effect of I₂ on the homogeneity of glass samples and the glass transitio n temperature was analyzed;The spectral properties of the glasses were studied by spectrophotometer and infrared spectrometer,and the effects of I₂ on the short wave absorption and infrared transmittance of the glass were analyzed;Raman spectroscopy was used to study the structural changes of the glass network.The experimental results show that the average molar volume of glass increases and T_g decreases with the increasing of I₂ content in glass.The thermal stability is improved,which has a maximum ofΔT_{m ax}=174°C.While the optical bandgap has a peak value at x=10 wt.%.The short wavelength absorption edge has a blue-shift,which improves the spectral transmittance of the glass.The absorption spectra and mid-infrared fluorescence spectra of Dy³⁺rare-earth ions doped glasses were investigated together with the Judd-Ofelt analysis.GeS₂ nano-crystals were found in the sample with x≥15 wt.%,which is supposed to induce enhancements of mid-infrared fluorescence at 2.95 and 4.32μm.The results of this study provides a superior and environment-friendly candidate material in design and manufacture of high performance infrared laser（or amplifier）and infrared sensor.