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Abstract: Multicomponent telluride-tungstate glasses containing Nd3+ and Er3+ ions were studied experimentally at 77 and 293K using spectroscopic methods. The Judd–Ofelt intensity parameters were derived from the absorption spectra and used to calculate the radiative lifetimes and branching ratios. The quantum efficiency η =0.95 of the 4F3/2 level of Nd3+ ion is higher than the typical value of other tellurite-based glasses. For low concentration of Er3+ ions, the luminescence decay of the 4S3/2 and 4I11/2 levels is governed by radiative transitions and multiphonon relaxation involving the Te-O highest energy vibrations. [Copyright &y& Elsevier]

Abstract: The paper presents the synthesis and spectroscopic properties of 46PbO:53P2O5:Ln2O3 glasses, where Ln=Sm or 0.1Sm+0.9Gd. The glasses show intense luminescence dominated by the orange 4G5/2 → 6H7/2 transition. The luminescence branching ratios and quantum yields have been computed using the Judd–Ofelt analysis of relevant absorption spectra and the observed luminescence lifetimes; the maximum found quantum yield was 69%. The lifetimes and the quantum yields depended on the time of heating the samples at high temperature and on the samarium concentration. [Copyright &y& Elsevier]

Abstract: Non hygroscopic U3+:KPb2Cl5 single crystals with a 0.1mol% U3+ nominal concentration and good optical quality have been obtained by the Bridgman–Stockbarger method. High-resolution absorption and emission spectra of the crystals were recorded at room temperature in the 4000–25000cm−1 and 4000–14000cm−1 spectral ranges, respectively. Excitation in the spectral region of 5f3 →5f26d1 transitions produced a strong near infrared emission from the 4F3/2 and 4I11/2 energy levels. A Judd–Ofelt intensity analysis has been performed in order to describe the electric dipole strengths of the observed transitions. The obtained phenomenological parameters were used to predict luminescence properties of U3+ ions doped in the KPb2Cl5 single crystal. [Copyright &y& Elsevier]

Highlights: [•] Nd,Y:CaF2 crystals with diameter 3-inch were grown by TGT method. [•] Optical spectra of Nd,Y:CaF2 crystals were recorded at different temperatures. [•] Broad and flat emission spectra of Nd3+ ions were obtained by Y3+-codoping. [ABSTRACT FROM AUTHOR]

Abstract: Upon UV–VUV excitation terbium doped K5Li2LaF10 emits white light coming from the 5D3 and 5D4 multiplets for content of Tb3+ up to 10at%. For higher concentrations (80 and 100at%) the emission becomes green. In excitation spectrum, recorded at 12K, the positions of the zero-phonon lines are not well determined. The spin allowed f–d transitions in this spectrum are similar to the cerium one in K5Li2LaF10: Ce3+, as van Pieterson proposed in the frames of Dorenbos’ model. The maxima of these terbium f–d transitions are found at: 46,976, 57,124, 59,404, 60,629 and 67,110cm−1. The lowest forbidden, high-spin d band is situated at 39,193cm−1. The lifetime of the 5D4 multiplet is 7.5ms and does not depend on the terbium concentration, but the 5D3 lifetimes are strongly influenced and amount to: 2710, 2130, 14.1, 9.5μs for 2, 10, 80, 100at% of terbium, respectively. This is in agreement with the colour rendering of these samples. [Copyright &y& Elsevier]