RESUMO
We theoretically and numerically investigate metal enhanced fluorescence of plasmonic core-shell nanoparticles doped with rare earth (RE) ions. Particle shape and size are engineered to maximize the average enhancement factor (AEF) of the overall doped shell. We show that the highest enhancement (11 in the visible and 7 in the near-infrared) is achieved by tuning either the dipolar or the quadrupolar particle resonance to the rare earth ion's excitation wavelength. Additionally, the calculated AEFs are compared to experimental data reported in the literature, obtained in similar conditions (plasmon mediated enhancement) or when a metal-RE energy transfer mechanism is involved.
Assuntos
Nanopartículas Metálicas/química , Metais/química , Espectrometria de Fluorescência , Transferência de Energia , Fluorescência , Íons , Luminescência , Teste de Materiais , Metais Terras Raras , Nanopartículas , Nanotubos/química , Ressonância de Plasmônio de Superfície , Propriedades de SuperfícieRESUMO
Ytterbium doped fiber lasers are known to be impacted by the creation of color centers during lasing so called photodarkening. This defect creation was investigated in a spectroscopic point of view, showing the presence of thulium traces (ppb) in the ytterbium doped fiber. Moreover, this contamination exhibit luminescence in the UV range under 976 nm excitation of the ytterbium-doped fiber. In adding more thulium to an ytterbium-doped fiber it was shown that thulium strongly impact the defects creation process, involved in photodarkening.
Assuntos
Artefatos , Tecnologia de Fibra Óptica/instrumentação , Lasers , Túlio/química , Itérbio/química , Desenho de Equipamento , Análise de Falha de EquipamentoRESUMO
Site distributions of Er(3+)-doped aluminosilicate preforms of standard EDFA were studied by the low temperature Resonant Fluorescence Line Narrowing (RFLN) spectroscopy. Two erbium concentration samples with the same glass base were investigated. At very low erbium concentration, two classes of sites were identified, related to the number of AlO(6) octahedral linked by two oxygen edge-sharing to Er(3+) in the coordination sphere. As erbium concentration is increased, the high AlO(6) coordinated class of sites is smeared out by the optical response of the one AlO(6) coordinated class of sites.
