J. Phys. IV France 04 (1994) C4-501-C4-504
Mechanisms of up-conversion excitation of blue emission in YAG:Tm, YbA. KNÜPFER1, V. OSTROUMOV1, E. HEUMANN1, G. HUBER1 and V. LUPEI2
1 Universität Hamburg, Institut für Laser-Physik, Jungiusstrasse 11, 20355 Hamburg, Germany
2 Institute of Atomic Physics, Bucharest 76900, Romania
Trivalent ytterbium ions were used as sensitizers for the 1D2 and 1G4 blue emitting thulium levels. The evolution of the population of the 1D2, 1G4, 3H4, 3F4 levels of Tm3+ and the 2F5/2 level of Yb3+ were investigated after short resonant excitation into these levels in YAG:Tm, Yb crystals. We observed upconversion fluorescence with a fast cooperative process followed by a slower step-by-step-process.
© EDP Sciences 1994