Upconverted green-yellow emission has been generated at room temperature in
Y3Al5O12: Sm3- crystals after pulsed 925-950 nm infra-red excitation. The
dynamics of the involved excited states were analyzed under pulsed laser ex
citation. The upconversion mechanisms were investigated and shown to be qua
si-resonant energy transfers. (C) 2001 Elsevier Science B.V. All rights res
erved.