LAERCIO GOMES
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Resumo IPEN-doc 29660 Study of neodymium laser transition in glasses and influence of up-conversion processes under diode pumping2003 - COURROL, LILIA C.; KASSAB, LUCIANA R.P.; DEL CACHO, VANESSA; WETTER, NIKLAUS U.; GOMES, LAERCIO; VIEIRA JUNIOR, NILSON D.; MESSADDEQ, YOUNES; RIBEIRO, SIDNEY J.L.By solving the rate equations including upconversion for Nd glass hosts under continuous diode pumping, it was possible to calculate the nonlinear behavior of the pumping efficiency and threshold pump intensity as a function of exited-state population.Resumo IPEN-doc 24514 Upconversion luminescence of Yb3+: Tm3+ and Yb3+: Tm3+: Er3+- doped Beta-Tricalcium Phosphate nanoparticles2017 - SILVA, F.R.O.; LIMA, N.B.; BRESSIANI, A.H.A.; GOMES, L.A novel class of fluorescence nanoparticles of 5.5 mol% of Yb3+, 0.5 mol% of Er3+ and 0.5 mol% Tm3+: calcium deficient hydroxyapatite were synthesized by co-precipitation method in aqueous solution (pH adjusted to 6) and specially treated with microwave radiation at 1000°C for 10 minutes to produce nanocrystals of Yb:Tm: and Yb:Tm:Er:-tricalcium phosphate (-TCP). As a result, we report for the first time, a single-phase -TCP:Yb:Tm:Er and -TCP:Yb:Tm exhibiting an efficient visible and near infrared upconversion luminescence from the 1G4 (blue emission), 4S3/2 (green emission), 3F2 (red emission) and 3H4 (near infrared emission) induced by the Yb3+ Tm3+ / Er3+ energy transfer under pulsed laser excitation at 972 nm (Yb3+) with an average energy of 11 mJ. The emission decay curves of the upconversion transients, from 1G4 excited state of Tm3+ and 4S3/2 excited level of Er3+, indicate that ESA process occurs in -TCP:Yb/Tm/Er nanopowder measured for the 550 nm luminescence of Er3+, which has a time constant (t2) of 0.4 s. However, Yb3+ Tm3+ upconversion (Up2) has a time constant (t2) of 14.4 s and does not exhibit ESA absorption. This -TCP activated by Yb3+ and Tm3+ ions constitutes a new nanobiomaterial that can be used as diagnostic and therapeutic agents, affording deeper tissue penetration and higher resolution and sensitivity for visible-near infrared bioimaging and treatments.Resumo IPEN-doc 23682 Yb:Er-doped LiLa(WO4)2 single crystal fiber growth2016 - DENALDI, R.L.; BALDOCHI, S.L.; GOMES, L.; MAZZOCCHI, V.L.; MORAES, J.R.; PARENTE, C.B.R.Resumo IPEN-doc 08436 Investigation of the Tm -> Ho enerrgy transfer and upconversion losses in diode-pumped LiYF(sub 4)1997 - TARELHO, L.V.G.; PEIRO, G.P.; GOMES, L.; RANIERI, I.M.; VIEIRA JUNIOR, NILSON D.Resumo IPEN-doc 07514 The up-conversion processes efficiency in diode pumped Nd:GdLiF(sub 4)1998 - COURROL, L.C.; MALDONADO, E.P.; GOMES, L.; VIEIRA JUNIOR, NILSON D.; RANIERI, I.M.Resumo IPEN-doc 14437 Growth and characterization of BaYsub(2)Fsub(8):Nd:Dy2007 - CRUZ, S.F.A.; GOMES, L.; BALDOCHI, S.L.Resumo IPEN-doc 10374 Spectroscopic characterization of ejected dental tissue by Er:YAG lases2001 - COURROL, L.C.; ZEZELL, D.M.; SAMAD, R.E.; GOMES, L.Resumo IPEN-doc 02891 Espectroscopia do Nd:YLF sob excitacao com laser de diodo1996 - COURROL, L.C.; MALDONADO, E.P.; GOMES, L.; VIEIRA JUNIOR, N.D.; RANIERI, I.M.; MORAES, N.M.P.; MORATO, S.P.Resumo IPEN-doc 02892 Conversao ascendente do infravermelho para o visivel em cristais de YLF dopados com Tm e Ho1996 - TARELHO, L.V.G.; MALDONADO, E.P.; PEREZ PEIRO, G.; GOMES, L.; VIEIRA JUNIOR, N.D.; RANIERI, I.M.; MORATO, S.P.Resumo IPEN-doc 02890 Propriedades espectrais e temporais dos processos de relaxacao cruzada entre ions de Tm no YLF1996 - TARELHO, L.V.G.; GOMES, L.; RANIERI, I.M.; MORATO, S.P.