Optical spectroscopy of Er3+-doped LaVO4 crystal

Transparent single crystals of erbium-doped LaVO4 in form of platelets having an average size 0.5×2×2 mm3 were obtained by the flux method using Pb2V2O7 as the solvent. Inductively coupled plasma (ICP) measurement revealed that the actual Er/La=0.3% molar ratio in the crystals is lower than Er/La=1% nominal molar ratio due to significant difference of ionic radii of La and Er. Luminescence spectra and luminescence decay curves for Er3+ transitions in the visible and near infrared region were recorded. Unpolarized Raman spectrum of undoped LaVO4 crystal was acquired, too. Up-converted green emission following excitation at 808 and 970 nm was observed and dependence of its intensity on incident excitation power was determined. Based on experimental data gathered the relaxation dynamics of excited states of Er3+ was analyzed and mechanisms involved in the up-conversion phenomena were discussed.