Yb3+-doped Gd3Ga5O12 garnet single crystals grown by the micro-pulling down technique for laser application. Part I: Spectroscopic properties and assignment of energy levels

Spectroscopic characterization were carried out to identify Stark's levels of Yb3+ transitions in the Gd3+ dodecahedral S4 crystallographic site in Gd3Ga5O12 garnet crystals which are grown by the micro-pulling down technique. Yb3+ concentration dependence of the 2F5/2 excited level experimental decay time was analyzed in order to understand involved concentration quenching mechanisms.