Crystal growth, polarized spectral properties, and 2.3 µm laser performance of Tm:LuVO4 crystal

Abstract

We report on the Czochralski crystal growth, polarized optical spectroscopy, and the first continuous-wave laser operation of 1.5 at.% Tm:LuVO4 crystal on the 3H4 → 3H5 transition. The polarized absorption and stimulated-emission properties of Tm3+ ions in LuVO4 were revised and the crystal-field splitting of the Tm3+ multiplets was determined by low-temperature (12 K) spectroscopy. The maximum stimulated-emission cross-section for the 3H4 → 3H5 transition is 2.48 × 10−20 cm2 at 2363 nm for π-polarization corresponding to an emission bandwidth of 28 nm. Evidence of phonon-assisted emissions of Tm3+ ions above 2 µm is presented. The broadband emission properties of the Tm:LuVO4 crystal make it promising for ultrashort pulse generation. Additionally, pumped by a 796 nm fiber-coupled laser diode, the Tm:LuVO4 laser generated a Watt-level output power at 2279-2295 nm with a slope efficiency of 9.2% and linearly polarized emission (π-polarization).