Effect of dopant concentration on the spectra characteristic in Zr4+ doped Yb:Nd:LiNbO3 crystals

Abstract A series of Yb:Nd:LiNbO 3 crystals tridoped with various concentrations of Zr 4+ (1 mol.%, 2 mol.% and 4 mol.%) were grown by the Czochralski technique from the congruent melt. The X-ray powder diffraction, UV-Vis-NIR absorption spectra and IR transmittance spectra were measured to analyze the crystal composition and defect structure. The Zr 4+ , Yb 3+ and Nd 3+ ions in LiNbO 3 crystal had two effects: volume compensation effect and ion valence state compensation effect. The ZrO 2 doping threshold concentration was nearly 2.0 mol.%. The fluorescence emissions of Nd 3+ ions and Yb 3+ ions were observed under 808 nm excitation. The intensity of fluorescence emissions enhanced with the increasing of the Zr 4+ doping concentrations. The Zr:Yb:Nd:LiNbO 3 crystals with 4 mol.% doping concentration of Zr 4+ ion revealed strong emission around 1 μm, which is of great significance for laser materials.