Influence of Li and Nb ratios on the defect structure and exposure energy in LiNbO3:Fe:Mn:Zr crystals

Research highlights: → We measured the Zr concentration and Li/Nb ratios in the crystals accurately via inductively coupled plasma atomic emission spectrometer. → We used the results of ultraviolet visible absorption spectra to conclude the defect structure of the crystals. → We proposed a quantitative method to scale light-induced scattering in LiNbO3:Fe:Mn:Zr crystals. → This method could consider the influence of irradiation time on light-induced scattering. - Abstract: A series of LiNbO3:Fe:Mn:Zr crystals with different ratios of Li/Nb in the melt (0.94,1.05,1.20 and 1.38, respectively) were grown by the conventional Czochralski technique. The ultraviolet-visible spectra were measured in order to analyze the defect structure of the crystals. The measurement of the Zr concentrations and Li/Nb ratios in the crystals was carried out with an inductively coupled plasma atomic emission spectrometer. The light-induced scattering was investigated as a function of exposure energy. The results showed that the ability to resist the light-induced scattering was improved considerably with the increase of the Li/Nb ratio. The relationship between the defect structures and the light-induced scattering was discussed.