Concentration-dependent energy-transfer processes in Er^3+- and Tm^3+-doped heavy-metal fluoride glass

Abstract
The energy-transfer rate from the Er3+ 4I13/2 level to the Tm3+ 3H4 level (C11′NT) in BaF2/ThF4 fluoride glass is measured and calculated. The results can be used to determine whether rate equations can be used to predict energy-transfer rates.