Spectroscopic analysis and laser parameters of Nd3+ in Ca3Sc2Ge3O12 garnetcrystals

Ca3Sc2Ge3O12 (CaSGG) single crystals with the garnet structure have been gr own by means of the flux growth technique. The doping with Nd3+ and Mg2+ (a s charge compensator) yields samples suitable for optical spectroscopy expe riments. The absorption and emission properties have been measured at tempe ratures ranging from 10 to 298 K. The emission spectra give evidence of the presence of non-equivalent Nd3+ sites. The decay time of the 1.06-mu m emi ssion band has been measured as a function of temperature and incident powe r. The intensities of the 298 K absorption transitions have been analyzed b y means of the Judd-Ofelt theory. The radiative lifetimes, the branching ra tios (beta), and the spontaneous emission probabilities have been evaluated for the F-4(3/2) excited state using the calculated intensity parameters. The stimulated-emission cross sections and the branching ratios have been e stimated from the experimental data for the most important laser transition s indicating that this crystal can be considered an interesting material fo r solid-state laser applications.