Optical spectroscopy, 1.5 μm emission and up-conversion properties of Er3+-doped Li3Ba2Gd3(MoO4)8 crystal

► Er3+:Li3Ba2Gd3(MoO4)8 crystal was grown by the top seed solution growth method. ► Spectroscopic parameters of the crystal were investigated based on the Judd-Ofelt theory. ► Emission cross-sections were calculated by the Fuchtbauer-Ladenburg formula. ► Up-conversion fluorescence spectra were measured and the mechanisms were proposed.