Oliveira, A. S.Gouveia, E. A.de Araujo, M. T.Gouveia-Neto, A. S.de Araujo, C. B.Messaddeq, Younes [UNESP]2014-05-202014-05-202000-05-01Journal of Applied Physics. Melville: Amer Inst Physics, v. 87, n. 9, p. 4274-4278, 2000.0021-8979http://hdl.handle.net/11449/32467Infrared-to-visible upconversion emission enhancement through thermal effects in Yb3+-sensitized Pr3+-doped fluoroindate glasses excited at 1.064 mu m is investigated. A twentyfold increase in the 485 nm blue emission intensity as the sample temperature was varied from 20 to 260 degrees C was observed. The visible upconversion fluorescence enhancement is ascribed to the temperature dependent multiphonon-assisted anti-Stokes excitation of the ytterbium sensitizer and excited-state absorption of the praseodymium acceptor. A model based upon conventional rate equations considering a temperature dependent effective absorption cross section for the F-2(7/2)-->F-2(5/2) transition of the Yb3+ and (1)G(4)-->P-3(0) excited-state absorption of the Pr3+, agrees very well with the experimental results. (C) 2000 American Institute of Physics. [S0021-8979(00)08209-8].4274-4278engArtigo10.1063/1.373065WOS:000086724100036Acesso abertoWOS000086724100036.pdf2998503841917815