Highly confined gap surface plasmon modes in metal strip–gap–film configurations

Abstract:

Plasmonic waveguides supporting gap surface plasmon (GSP) modes localized in a deep subwavelength dielectric gap between a metal strip and underlay film are investigated numerically and experimentally at telecom wavelengths. Particularly, we demonstrate that GSP waveguides with only the top metal layer structured to form the waveguide, including nanoantenna couplers optimized for normal incident Gaussian beam excitation, can be fabricated in a single lithography step leading to 15% experimental coupling efficiency of GSP modes with ∼10  μm propagation length when the gap size is 10 times smaller than the free-space wavelength.

Año de publicación:

2015

Keywords:

Fuente:

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