Thermo-optical and spectroscopic properties of Nd:YAG fine grain ceramics: towards a better performance than the Nd:YAG laser crystals

In this work, we investigated the thermo-optical properties of highly Nd3+ doped YAG ceramics. The normalized lifetime thermal lens method was used to obtain the fluorescence quantum efficiency (eta) versus Nd3+ concentration (N-t) and to study the energy transfer microparameters C-DD and C-DA. The N-t dependence of eta was compared to the results of the previous literature. The C-DA found is very similar to those of the previous literature, while the C-DD is very different and higher than C-DA, although the main dependence of eta with N-t is assigned to C-DA. The figure of merit (eta.N-t versus N-t) indicated a maximum around 3.8 at.% Nd2O3, which in addition to the very low ds/dT value, evidences the YAG ceramic as an excellent material for an ultra-high-power microchip laser system and for devices requiring minimum pump-induced local heating generation.