Czochralski growth and optical investigations of Er3+:GdTaO4 laser crystal

Highly doped Er3+:GdTaO4 crystal was grown successfully by the Czochralski(CZ) method for the first time. The crystal structure was determined by Rietveld refinement to X-ray powder diffraction. The absorption and photoluminescence spectra at room temperature were investigated. The Judd-Ofelt transition intensity parameters Ωt (t=2, 4, 6) were fitted to its absorption spectrum. With parameters Ωt, the oscillator strengths, fluorescence branching ratios, transition probabilities and the lifetimes of Er3+:GdTaO4 were calculated. The near-infrared and mid-infrared fluorescence properties were also analyzed and discussed. The results show that the Er3+:GdTaO4 crystal may be regarded as a potential solid-state laser material for 2.6μm.