Sensitization of MIR Tb3+ luminescence by Tm3+ ions in CsCdBr3 and KPb2Cl5 crystals

Energy transfer process from Tm3+ ions to Tb3+ ions was investigated in CsCdBr3:Tb,Tm and KPb2Cl5:Tb,Tm crystals. Energy transfer quantum efficiency were found as high as qtr = 68 % for the CsCdBr3:Tm(1.0%),Tb(0.5%) crystal and qtr = 22% for the KPb2Cl5:Tm(2.5%),Tb(0.2%) crystal. It is shown that they are promising candidates as laser crystals for MIR, suitable for diode laser pumping at 0.8 μm in Tm3+ absorption band.