Sensitized Yb3+ emission in (Nd, Yb):Y3Al5O12 transparent ceramics

Abstract

The characteristics of Nd→Yb energy transfer in (Nd, Yb):Y3Al5O12 (YAG) transparent ceramics, obtained from steady state and dynamic spectral studies on different single doped and codoped samples, prepared by solid state synthesis, are presented. The Yb3+ emission in codoped (Nd, Yb):YAG samples under cw excitation of the donors (Nd3+) revealed efficient energy transfer to Yb3+ (at low temperatures too), due to the overlap of the Nd3+ F43/2→I49/2 emission and Yb3+ F27/2→F25/2 absorption. From the global decays of the Nd3+ F43/2 level in single and codoped samples, the transfer efficiencies were estimated; they increase with Yb3+ content reaching ∼93% for 1 at. % Nd, 5 at. % Yb:YAG sample. The mechanisms and parameters of the Nd→Yb energy transfer were inferred from the Nd3+ decays in the codoped samples, after the separation of the self-quenching inside the donors (Nd3+) from the transfer to acceptors (Yb3+). It was proved that the Nd→Yb energy is resonant and dominated by dipole-dipole interactions. Due to the large transfer efficiencies, (Nd, Yb):YAG ceramic could be a promising material for Yb3+ emission under pumping in strong Nd3+ absorption lines.