The effect of Zn2+ ion on the UV–VIS–NIR and upconversion emission spectroscopy of Er3+ in Yb:Er:LiNbO3 crystal

A series of Yb:Er:LiNbO3 crystals tridoped with x mol% Zn2+ ions (x = 1, 3, 5 and 8 mol%) was grown by Czochralski technique. The inductively coupled plasma atomic emission spectrometry (ICP-AES) was used to measure the concentration of Er3+ in the crystal. The UV–VIS–NIR absorption spectra of Zn:Yb:Er:LiNbO3 crystals were measured, and Judd–Ofelt (J–O) theory was applied to predict the J–O intensity parameters (Ωt) and spectroscopic quality factor (X). With 980 nm excitation, duration lengthening of 1.54 μm emission and intensity enhancement of green upconversion emission were observed for Zn:Yb:Er:LiNbO3 crystal.