Efficient Nd 3 + → Yb 3 + energy transfer in Nd 3 + , Yb 3 + : Gd 3 Ga 5 O 12 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, Yb 3 + , Nd 3 + : Gd 3 Ga 5 O 12 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 Nd 3 + F 4 3 / 2 → Yb 3 + F 2 5 / 2 energy transfer was found whereas the back transfer was completely quenched at low temperature ( T < 200 K ) . From the data of Nd 3 + 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 cm 6 s − 1 at 300 K.