Effect of temperature on spectroscopic features relevant to laser performance of YVO4:Tm3+, GdVO4:Tm3+, and LuVO4:Tm3+ crystals

Optical spectra and luminescence decay curves were measured for thulium-doped YVO4, GdVO4, and LuVO4 single crystals as a function of temperature in the 300-670 K temperature region. In spite of structural similarity, the three systems studied display significantly different transition intensities and nonradiative relaxation rates. It was found, in particular, that the peak value of the pump band absorption intensity diminishes by about 30% for Tm:YVO4 and Tm:GdVO4, and the effective emission cross section for the laser transition of Tm3+ diminishes by a factor of 2 roughly when temperature increases from 300 to 500 K. An unusually small quantum efficiency of the upper laser level in Tm:LuVO4 has been derived from the analysis of luminescence decay curves. (C) 2010 Optical Society of America