Yellow laser potential of cubic Ca3(Nb,Ga)5O12:Dy3+ and Ca3(Li,Nb,Ga)5O12:Dy3+ single crystals

Spectroscopic investigation of Dy3+ doped Ca3(Nb,Ga)5O12 (CNGG) and Ca3(Li,Nb,Ga)5O12 (CLNGG) single crystals were performed in order to assess their potential as laser materials for yellow emission. Dy:CNGG and Dy:CLNGG single crystals were grown by the Czochralski method and investigated by high-resolution spectroscopic measurements for the first time. The Judd-Ofelt intensity parameters for the f-f transitions of Dy3+ in CNGG and CLNGG single crystals, were used to determine radiative transition rates Ar, branching ratios β, and radiative lifetime τr of the fluorescent Dy3+ levels. Based on low temperature absorption and emission spectra, partial energy levels diagram of Dy3+ doped CNGG and CLNGG single crystals were obtained. The emission cross-sections for the 4F9/2 → 6H13/2 transition of special interest for laser application were determined. The room temperature decay curves were analyzed through the framework of Inokuti-Hirayama (I-H) model and the results shows that electric dipole-dipole interaction are responsible for the energy transfer processes between Dy3+ ions in CNGG and CLNGG single crystals.