JONAS JAKUTIS NETO
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Resumo IPEN-doc 13612 The influence of silver nanoparticles in the Ybsup(3+) - Ersup(3+) energy transfer mechanism of PbO-GeOsub(2) glasses2008 - BOMFIM, F.A.; KASSAB, L.R.P.; MARTINELLI, J.R.; NETO, J.J.; WETTER, N.U.; ARAUJO, C.B. deThe influence of silver nanoparticles (NPs) on the frequency upconversion due to the energy transfer between erbium (Fr*) and ytterbium (Yb") ions in a co-doped glass is reported for the first time Erbium doped glasses have been studied and used in a variety of photonic applications. Nevertheless, efficient pumping of this ion is limited by the low absorption cross-section of Fr** around 980 nm that can be improved by co-doping the material with Yb* jons [1]. Recently, Er®* doped lead-germanate glasses containing silver NPs were studicd [2], Lead-germanate glasses are excellent materlals ſor photonic applications due to their high mechanical resistance, high chemical durability and thermal Stability, large transmission window (400 to 4500 nm), high refractive index. large nonlinear optical response, and low cutoff phonon energy (400 - 800 cm™) [3]. Besides, these glasses have proved to be good hosts for NPs nucleation [2]. To the basic glass composition 41Pb0-59.0Ge0, (in mol%) we added 0.5 wt% of Erz0z, 3.0 wi% of YbJO, and 1.0 wt% of AgNO;; the samples were obtained melting the starting oxide powers. quenching and annealing during different times to reduce the Ag’ ions to Ag’ in order to nucleate silver NPs. Measurements of (ransmission electron microscopy were performed and the visible upconversion spectrum was measured by optically pumping the sample with a high power CW diode laser emitting 5 W at 980 nm. Emission bands centered at 524, 547, and 659 nm were abserved corresponding 10 *Hi1g — 5o 'S42 — 15, and Fay — 1152 transitions of Fr' ions, respectively. Measurements of the upconversion intensity as a function of the laser power were performed. The influence of silver NPs in the Yb* — Er"” energy transfer mechanism is discussed and is attributed to the Influence of the surface plasmon resonance (associated to the NPs) that favors the emissions in the green region in comparison with the red emission. We remark that in the absence of the silver NPs green and red emissions have almost the same intensity.Artigo IPEN-doc 11444 Medição de alta resolução de fluorescência de fibras ópticas excitadas no infravermelho2005 - JAKUTIS NETO, JONAS; KASSAB, LUCIANA R.P.; HORA, WINDSON G.; MARTINELLI, JOSE R.; SENE, FRANK F.; WETTER, NIKLAUS U.Artigo IPEN-doc 11779 Producao e caracterizacao de fibras opticas de GeOsub(2)-PbO-Nbsub(2)Osub(5) dopadas com Ersup(3+)2006 - BOMFIM JUNIOR, FRANCISCO A.; KASSAB, LUCIANA R.P.; JAKUTIS NETO, JONAS; SENE, FRANK F.; MARTINELLI, JOSE R.; WETTER, NIKLAUS U.Reportamos neste trabalho o método de fabricação e caracterização de fibras vítreas de germanato à base de GeO2–PbO–Nb2O5 (GPN). Através dos espectros de emissão da fibra notamos a possibilidade de aplicações com dispositivos ópticos para as regiões do visível e do infravermelho.Artigo IPEN-doc 13154 Efeito da concentração de Ybsup(3+) na luminescência de conversão ascendente do Ersup(3+) em vidros de PbO-GeOsub(2)-GHasub(2)Osub(3)2008 - BOMFIM JUNIOR, FRANCISCO A.; KASSAB, LUCIANA R.P.; MARTINELLI, JOSE R.; WETTER, NIKLAUS U.; JAKUTIS NETO, JONASArtigo IPEN-doc 13155 Energy transfer and frequency upconversion in Ybsup(3+)-Ersup(3+) doped PbO-GeOsub(2) glass containing silver nanoparticles2009 - KASSAB, L.R.P.; BOMFIM, F.A.; MARTINELLI, J.R.; WETTER, N.U.; NETO, J.J.; ARAUJO, CID B. deWe report the infrared-to-visible frequency upconversion in Er3+–Yb3+-codoped PbO-GeO2 glass containing silver nanoparticles (NPs). The optical excitation is made with a laser at 980 nm in resonance with the 2F5/2→2F7/2 transition of Yb3+ ions. Intense emission bands centered at 525, 550, and 662 nm were observed corresponding to Er3+ transitions. The simultaneous influence of the Yb3+→Er3+ energy transfer and the contribution of the intensified local field effect due to the silver NPs give origin to the enhancement of the whole frequency upconversion spectra.