Tunability of subradiant dipolar and fano-type plasmon resonances in metallic ring/disk cavities: implications for nanoscale optical sensing.
Plasmonic nanocavities consisting of the concentric arrangement of a disk and a ring sustain both subradiant and superradiant dipolar plasmon modes with large associated field enhancements and high refractive index sensitivities. In structures with broken symmetry, additionally a highly tunable Fano interference feature appears, which can be explained with a simple analytical harmonic oscillator model. The spectral tunability of these resonances from the visible to the mid-infrared is investigated, highlighting a potential for applications in surface enhanced spectroscopies.
Hao
Feng
F
Laboratory for Nanophotonics, Department of Physics and Astronomy, Rice University, Houston, Texas 77005-1892, USA.
Nordlander
Peter
P
Sonnefraud
Yannick
Y
Van Dorpe
Pol
P
Maier
Stefan A
SA