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Abstract: Large crystals of pure and Y b3+ doped NaY (MoO4)2 have been grown using the Czochralski method. The major problem with these crystals is that they are black in colour, causeing total absorption in the visible range, this was resolved by annealing and the nature of the colour defect was discussed. Measurements such as DTA, thermal expansion in different crystallographic directions, and refractive index as a function of wavelength were investigated. The broad absorption band at about 980 nm and high value of the absorption cross-section are obtained for the Y b3+ doped crystal. The results show that Y b3+:NaY (MoO4)2 crystal has potential as a promising laser crystal. [Copyright &y& Elsevier]

Abstract: crystal with the size up to 13 mm×44 mm was grown successfully by the Czochralski technique and its optical properties were presented. The absorption cross-section and emission cross-section were presented. Also, the potential laser gain near 1.9 μm was investigated. In the framework of the Judd–Ofelt (J–O) theory, the intensity parameters were calculated to be: Ω2=11.375×10−20 cm2, Ω4=5.077×10−20 cm2 and Ω6=6.524×10−20 cm2. The spectroscopic parameters of this crystal such as the oscillator strengths, radiative transition probabilities, radiative lifetime as well as the branching ratios were calculated, too. This crystal is promising as a tunable infrared laser crystal. [Copyright &y& Elsevier]

Abstract: Tm3+:SrWO4 crystal of good optical quality with sizes of 15mm×60mm was grown successfully by Czochralski technique method. The orientation procedure of this crystal was discussed. The principal coefficients of thermal expansion along (001), (010), (100) directions were precisely measured to be 2.73×10−5, 1.00×10−5, 1.05×10−5 °C−1, respectively. Based on the Judd–Ofelt theory, we obtained the three intensity parameters: Ω 2=7.41×10−20, Ω 4=0.25×10−20, and Ω 6=1.71×10−20 cm2. The radiative probabilities, radiative life times, and branch ratios of Tm3+:SrWO4 were calculated. The room temperature polarized fluorescent spectra and fluorescent decay curve were measured. The luminescent quantum efficiency of the 3H4 level was investigated and the quantum efficiency is determined to be approximately 69.84% for this material. [Copyright &y& Elsevier]