EXPERIMENTAL-DETERMINATION OF RADIATIVE-TRANSITION RATES AND QUANTUM EFFICIENCIES IN ER3+YALO3

A method for the measurement of radiative-transition rates in rare-ear th-doped laser crystals with several metastable levels is presented. T he excited-state absorption in Er3+:YAlO3 is measured in a pump- and p robe-beam experiment. With this information the populations of the met astable levels (4)I1(3/2), I-4(11/2), and S-4(3/2) are derived. In com bination with data of the relative fluorescence intensities and fluore scence-decay curves the radiative rates and quantum ifficiencies of tr ansitions from these levels are experimentally determined. The results are compared to data from a Judd-Ofelt analysis.