Spatially resolved electron energy loss spectroscopy of crescent-shaped plasmonic antennas

článek v časopise ve Web of Science, Jimp

angličtina

We present a study of the optical properties of gold crescent-shaped antennas by means of electron energy loss spectroscopy. These structures exhibit particularly large field enhancement near their sharp features, support two non-degenerate dipolar (i.e., optically active) localised surface plasmon resonances, and are widely tunable by a choice of their shape and dimensions. Depending on the volume and shape, we resolved up to four plasmon resonances in metallic structures under study in the energy range of 0.8 - 2.4 eV: two dipolar and quadrupolar mode and a multimodal assembly. The boundary-element-method calculations reproduced the observed spectra and helped to identify the character of the resonances. The two lowest modes are of particular importance owing to their dipolar nature. Remarkably, they are both concentrated near the tips of the crescent, spectrally well resolved and their energies can be tuned between 0.8 - 1.5 eV and 1.2 - 2.0 eV, respectively. As the lower spectral range covers the telecommunication wavelengths 1.30 and 1.55 micro m, we envisage the possible use of such nanostructures in infrared communication technology.

Nanomaterials; Surface plasmons; Plasmonics; Subwavelength structures, nanostructures

KŘÁPEK, V.; KOH, A.; BŘÍNEK, L.; HRTOŇ, M.; TOMANEC, O.; KALOUSEK, R.; MAIER, S.; ŠIKOLA, T.

2015

27. 4. 2015

1094-4087

OPTICS EXPRESS

23

9

Spojené státy americké

11855

11867

13