Synthesis and spectroscopic studies of Tm^3+-doped KY3F1o single crystals

We examine the laser possibilities offered by Tm^3+-doped KY3F(10). After crystal growth and X-ray diffraction analysis, the optical properties of thulium ions in KY3Fio are determined for the first time. Absorption and emission spectra recorded at low temperatures are used to obtain a set of Stark sublevels, whereas the room-temperature absorption spectra have been allowed to fit the three phenomenological Judd-Ofelt (JO) parameters. The emission line strengths, branching ratios, and radiative lifetimes of levels from 3F(4) up to 1D(2) are then deduced. A comparison between the calculated lifetimes and the measured luminescence decay curves permits us to check the reliability of the JO analysis for this system. The potential of Tm:KY3F10 for laser emission from 3H(4) or 3F(4) emitting levels is briefly examined.