Generation of pronounced Fano resonances and tuning of subwavelength spatial light distribution in plasmonic pentamers

Data Storage Institute, (A*STAR) Agency for Science Technology and Research, 5 Engineering Drive 1, 117608 Singapore.
Optics Express (Impact Factor: 3.53). 03/2011; 19(6):4949-56. DOI: 10.1364/OE.19.004949
Source: PubMed

ABSTRACT Arrays of plasmonic pentamers consisting of five metallic nano-disks were designed and fabricated to achieve a pronounced Fano Resonance with polarization-independent far-field spectral response at normal incidence due to the structure symmetry of pentamers. A mass-spring coupled oscillator model was applied to study plasmon interactions among the nano-disks. It was found that the direction of the excitation light polarization can flexibly tune the spatial localization of near-field energy at sub-wavelength scales while the collective optical properties are kept constant. It can lead to a selective storage of excited energy down to sub-20 nm gap at a normal incident with a single light source.

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