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Abstract: Ho3+/Yb3+ codoped lanthanum–tungsten–tellurite (TWL) glasses are prepared by melt-quenching method. The Judd–Ofelt intensity parameters (Ωt t =2, 4, 6), radiative transition rates, radiative lifetimes, and branching ratios of Ho3+ are calculated based on the absorption spectrum to evaluate the spectroscopic properties of Ho3+ in TWL glass. The mid-infrared emission of the samples are investigated under the excitation of 980nm LD. The absorption, emission cross-sections and gain coefficient of Ho3+:5I7 → 5I8 are calculated. The energy transfer processes of Yb3+–Yb3+ and Yb3+–Ho3+ are analyzed, the results show that the Yb3+ ions can transfer their energy to Ho3+ ions with large energy transfer coefficient, and a maximum efficiency of 84%. [ABSTRACT FROM AUTHOR]

Abstract: Transparent oxyfluoride glass and glass ceramics doped with 3.0mol% Yb3+ and 0.5mol% Ho3+ ions have been prepared. The investigated samples show efficient 2.0μm emission. The absorption and emission cross sections corresponding to the 5I7–5I8 transitions of Ho3+ (at 2.0μm) have been calculated according to the McCumber theory. Glass sample heat-treated at 470°C has the maximum absorption and emission cross sections of 5.58×10−21 cm2 at 1949nm and 6.64×10−21 cm2 at 2034nm. The Yb3+–Ho3+ doped oxyfluoride glass ceramic exhibits an advantage for application in 2.0μm laser devices. [ABSTRACT FROM AUTHOR]

Abstract: Tm3+ and Ho3+ co-doped TeO2–ZnO–Bi2O3 (TZB) glasses were prepared by the conventional melt-quenching method. Two micrometre emission properties of the TZB glasses exited by 808nm Laser Diode (LD) were analyzed and discussed. The Judd–Ofelt parameters, spontaneous radiative transition probabilities and radiative lifetime of Ho3+ were calculated based on the absorption spectra by using Judd–Ofelt theory. The absorption spectra and fluorescence spectra were measured. The predicted spontaneous radiative transition rate of 5I7 → 5I8 of Ho3+ is as high as 466.8 s−1. The result of fluorescence spectra indicates that the maximum emission intensity of Ho3+ 2.0μm and of Tm3+ 1.47μm emission can be achieved at the concentration of 1mol% Tm2O3 and 1mol% Ho2O3 in TZB glasses. The maximum absorption and emission cross-section of Ho3+ near 2.0μm are 0.87×10−20 cm2 at 1951nm and 1.07×10−20 cm2 at 2047nm, respectively. [Copyright &y& Elsevier]

Abstract: The lead-free boron silicon bismuthate glasses were investigated in terms of their physical, optical and structural properties. The physical properties of these glasses have been explored by compositional variation of X-ray diffraction (XRD), differential thermal analysis (DTA) and density. The optical properties of theses glasses have been investigated by UV–Vis and mid-infrared transmittance spectra, and refractive index. The structure of these glasses has been characterized by infrared (IR) absorption and Raman spectra. [Copyright &y& Elsevier]