Lifetime measurements with the pinhole method in presence of radiation trapping: II -application to Yb3+ doped ceramics and crystals

In this paper, we present an experimental verification of a theoretical model for the evaluation of the results of the so-called pinhole method for the measurement of the upper level lifetime in doped optical materials where the resonant reabsorption of the emitted fluorescence determines significant radiation trapping effects. As an experimental verification of the model, we measured the lifetime of the upper laser level of Yb3+ in various crystals and ceramic samples usually employed for the realization of solid state laser sources. We verified that the previously reported model correctly predicts the intrinsic double exponential behavior of the fluorescence decay and also accounts for the effect of the short range reabsorption occurring with this specific measurement technique.