Spectroscopic properties of Tm3+/Ho3+ co-doped NaLa(WO4)2 single crystal

Tm3+/Ho3+ co-doped NaLa(WO4)2 single crystal was successfully grown by the Czochralski method. The crystal was characterized by room temperature absorption spectra, fluorescence spectra around 2 μm, up-conversion fluorescence and luminescence decay measurements. Spectroscopic properties related to the laser operation around 2 μm of Ho3+ ions have been evaluated. The energy level scheme and energy transfer processes of Tm3+ and Ho3+ were analyzed. The obtained spectroscopic results show the crystal is a potentially host for Ho3+ 2 μm infrared laser.