Enhanced Directed Radiative Surface Plasmon Emission from Periodically Corrugated Noble Metal Films

Autor: Carsten Thirstrup, Leiva Casemiro Oliveira, Helmut Neff, Antonio Marcus Nogueira Lima, Eloise Passos Rodrigures
Rok vydání: 2018
Předmět:
Zdroj: Plasmonics. 13:2021-2027
ISSN: 1557-1963
1557-1955
DOI: 10.1007/s11468-018-0718-2
Popis: Massively enhanced directed radiation emission from periodically corrugated thin gold and silver films at the surface plasmon resonance is reported. The optical setup comprises attenuated total reflection in a modified Kretschmann configuration, with the semi-transparent metal films placed at the base plate of a polymeric semi-cylinder. Experiments performed at a fixed wavelength confirm earlier observations on appearance of two symmetrically arranged first-order diffraction beams. These emanate under resonance conditions into the upper and lower half-spaces, the latter due to coupling of the non-radiating surface plasmon to an angularly directed radiative mode. Collimated incident and spectrally broadband radiation under resonance conditions likewise split into two symmetrically arranged first-order, but spectrally dispersed continuous, diffraction beams. For silver, unlike smooth metal films, the non-radiative surface plasmon (SP) also splits into two spectrally separated resonance dips at 550 and 700 nm. The spectral continuum in the SP-mediated radiative beam in the lower half-space resembles the complementary color feature of the absorbing SP-mode. Its intensity exceeds the isotropic radiative plasmon emission from smooth, weakly roughened SP-active gold metal layers by at least two orders of magnitude.
Databáze: OpenAIRE
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