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+) (4)F(3/2)-> Yb(3+) (2)F(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 2.1x10(-39) cm(6) s(-1) at 300 K.