Optical spectra and excited state dynamics of Sm3+-doped YVO4 and YPO4 crystals

Single crystals of YVO4 and YPO4 doped with Sm3+ have been grown by the flux growth method. Their polarized absorption spectra, the luminescence spectra and the emission decay profiles have been measured at room temperature. The absorption spectra have been analyzed in the frame of the Judd-Ofelt Theory, and the evaluated radiative branching ratios as well as the lifetimes of the emitting level are in substantial agreement with the experimental observations. The emission decay curves have been measured for two different values of concentration in order to obtain information about the energy transfer processes in the investigated materials