The excitation and emission obtained from an Er3+-doped tellurite glass with embedded silver nanoparticles (SNPs) through nanostructured surfaces consisting of a square lattice of nanoholes (squares or circles) in a silver thin film are addressed. The periodic nanostructures were fabricated with a focused gallium ion beam on a silver thin film deposited onto an Er3+-doped tellurite glass with embedded SNPs. The Er3+ microluminescence spectra were measured in the far field (510- to 590-nm wavelength range). The emission observed through the plasmonic nanoholes is caused by the excitation of the Er3+ ions via extraordinary optical transmission from the periodic nanostructures. Two coupling types are proposed: (i) one between the SNPs and the Er3+ ions (electric dipole type) and (ii) a resonant coupling between the SNPs (localized surface plasmon resonance) and a silver thin film (surface plasmon polariton). These two couplings modify the local field, which improves the emission intensity of Er3+. A dependence of the intensity emission with the geometrical shape of the nanoholes and the number of elements of the square lattice was observed. These findings can be very useful for nanophotonic device applications employing a transparent medium with optical gain.
Bibliographical noteFunding Information:
This research was financially supported by the Brazilian agencies Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP), and Conselho Nacional de Desenvolvimento Científico e Tecnológico under Centro de Pequisas de Ótica e Fotônica/Instituto Nacional de Óptica e Fotônica. Marcelo H. Gehlen acknowledges FAPESP for the financial support (Project Nos. 05/4617-6 and 07/8399-9). Fabio A. Ferri also acknowledges FAPESP for the financial support (Project No. 17/01089-6).
- rare earths
- subwavelength structures
- surface plasmons
- tellurite glasses