Crystal growth, Judd–Ofelt analysis and fluorescence properties of Tm3+: CaNb2O6 crystal

Tm3+-doped CaNb2O6 single crystal was successfully grown by the Czochralski technique. Based on the Judd–Ofelt theory, three spectroscopic parameters Ωt (t=2,4,6), radiative transition probabilities, radiative lifetimes, branching ratios and oscillator strengths were obtained according to the absorption spectra and the fluorescence spectra. Both the radiative lifetimes corresponding to the 3F4→3H6 transition for the bulk and the powder samples were recorded, and the final value of the radiative lifetime was obtained to be 2.25 ms, which indicates the existence of the luminescence re-absorption in the bulk sample. The corresponding quantum efficiency of the 3F4 level was calculated to be 96%.