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Amphiphilic complexes with luminescent rare earth metal ions suitable for Lanmuir-Blodgett (LB) deposition have been synthesized. LB monolayers with closely packed Eu complexes deposited directly on silver demonstrate significant far-field emission in contrast to the theoretical predictions of full quenching. Angular radiation and polarization patterns of the electric and magnetic dipole emission of Eu3+point to a high excitation efficiency of surface plasmon polaritons. Different luminescent behavior of closely packed emitters in comparison to diluted systems is tentatively attributed to the collective state of emitters in LB layers formed via near-field coupling with surface plasmons.more » « less
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We have studied poly(methyl methacrylate) (PMMA) films doped with rhodamine 6G and rhodamine B laser dyes as potential nonlinear material components for nanophotonics. For both dyes, the optimal concentrations, at which the emission excited via the two-photon-absorption (TPA) process is maximized, have been determined. Despite relatively large values of TPA cross sections obtained in this study, the characteristic pumping densities needed to observe pronounced nonlinear effects substantially exceed the laser damage threshold for Au or alternative plasmonic materials. This makes the studied laser dyes unsuitable for some of the intended nanophotonics applications.more » « less
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We have studied emission kinetics in dye-doped polymeric films (HITC:PMMA), deposited on top of glass and silver and embedded in Fabry–Perot cavities (metal-insulator-metal waveguides). For highly doped films on glass, we observed strong concentration quenching, as evidenced by a dramatic shortening of the emission kinetics, consistent with our previous studies. However, for the same dye-doped films on top of silver, slower emission kinetics were observed despite the high decay rates of individual dye molecules near the metallic surface. The concentration quenching rates in Fabry–Perot cavities were nearly identical to those of HITC:PMMA films deposited on top of silver. These findings are explained within a theoretical model for the inhibition of Förster energy transfer near a metallic surface. Furthermore, the emission kinetics of the dye-doped films on top of silver were approximately single exponential—consistent with the strong coupling of excited molecules with propagating surface plasmons.more » « less
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We have studied, both theoretically and experimentally, the excitation of volume modes in a lamellar metal/dielectric metamaterial with hyperbolic dispersion. The highly efficient light penetration through tens of metamaterial layers is consistent with a relatively low propagation loss. The volume modes were found to be highly sensitive to the surface roughness of the layers, which can be a detrimental factor in device applications.more » « less
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We fabricated and experimentally studied Au nano-foams and Al2O3 scaffolds filled with Au nanoparticles (NPs). We found that while the reflectance spectra of Au nano-foams depended very little on the 8-10 nm Al2O3 ALD coating, the spectra were highly sensitive to annealing, which increased the sizes of voids and ligaments from 50-100 nm to ∼300 nm. The effective dielectric permittivities of the Au nano-foams and Al2O3 scaffolds with Au NPs were extremely high, ∼50. At the same time, Au nano-foams covered with a dielectric (MgF2) featured bright structural colors, calling for the model, which extends beyond the effective medium approximation.more » « less
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