Optical properties of LiNbO3 crystals doped with Yb3+ ions

Abstract

Optical properties of Yb-doped LiNbO₃ crystals were investigated. The low temperature absorption and selective emission of LiNbO₃:Yb³⁺ crystals obtained by Montoya et al were reexamined. The LiNbO₃:Yb³⁺ crystals absorption and emission spectra show broad emission due to the presence of four non-equivalent sites: three octahedral sites (Li⁺ (S1), Nb⁵⁺(S2), and a vacant octahedron(S3)) and an interstitial tetrahedral site(S4) . Considering the presence of these four Yb³⁺ion-occupied sites, and also the electron-phonon coupling processes, the majority of emission and absorption lines was assigned. For the different observed optical centers in LiNbO₃, the experimental Stark energy levels of Yb³⁺ ions were established.