Optical properties of Sm doped Mg:LiNbO3 and Zn:LiNbO3 single crystals

Sm³⁺ doped Mg:LiNbO₃ and Zn:LiNbO₃ are grown by Czochralski method. Optical transmittance and emission spectra are measured and Judd-Ofelt theory is applied to determine phenomenological intensity parameters, oscillator strengths, radiant transition rates, total radiant lifetimes, and branching ratios. The calculations show that Judd-Ofelt parameters with the relation of Ω₄ > Ω₂ > Ω₆ exist, and ΣΩ_ξ (ξ = 2, 4 and 6) in Sm:Zn:LiNbO₃ decreases. Fluorescence spectra indicate that visible fluorescence of Sm³⁺ is made up of 570, 606, 613 and 654 nm emission bands in these crystals under 409 nm excitation.