Spectroscopic characteristics of the Nd3+ ions in garnet crystals

The article deals with the research of oscillator strengths and the Ω_t (t=2,4,6) intensity parameters of Nd³⁺ doped garnet crystals. It has been found that the absorption intensity of the ⁴I_9/2→⁴G_5/2, ²G_7/2 hypersensitive transition in the Ca₃(NbGa)₅O₁₂ crystals doped with Nd³⁺ is considerably higher than the corresponding values in the following garnet crystals: Y₃Al₅O₁₂:Nd, (GdY)₃(ScAl)₅O₁₂:Nd, Gd₃(ScAl)₅O₁₂:Nd and (GdСa)₃(GaZr)₅O₁₂:Nd. It has been established also that the Ω₂ intensity parameter of the Ca₃(NbGa)₅O₁₂:Nd crystals is one order of magnitude higher compared to the same parameter for the other garnet crystals. These effects in the Ca₃(NbGa)₅O₁₂:Nd crystals are explained by the presence of the Nd³⁺ ions optical sites with a symmetry of local environment C₂, C_2v, C₁.