Efficient Nd3+→Yb3+ energy transfer in Nd3+,Yb3+:Gd3Ga5O12 multicenter garnet crystal

For seeking better laser crystals with good optical properties and high efficiency, especially for application in a high power solid-state laser, Yb3+,Nd3+:Gd3Ga5O12 crystal (abbreviated as Yb,Nd:GGG below) was grown by Czochralski method. A complete optical characterization was reported including absorption and emission spectra at different temperatures and fluorescence lifetimes. Very efficient Nd3+ F43/2→Yb3+ F25/2 energy transfer was found whereas the back transfer was completely quenched at low temperature (T<200 K). From the data of Nd3+ fluorescence lifetime and emission spectrum we achieved the energy-transfer efficiency as large as 94% at 77 K and 84% at 300 K, respectively. After fitting the decay curve we got the energy-transfer microparameter with a value of 2.1×10−39 cm6 s−1 at 300 K.