Spectroscopic properties of Er:NaLa(WO4)2 crystals and effect of Ce codoping onto the excited state energy transformation in this crystal

► The Judd-Ofelt parameters of Er3+:NaLa(WO)4 crystal were calculated. ► The values of Er energy levels in NaLa(WO)4 crystal were presented. ► The presence of Ce helps the population of the Er 4I13/2 excited state in NaLa(WO)4.