Scattering Suppression and Field Enhancement of the Fundamental Plasmonic Mode in Bent Nanorods

作者：Pors Anders^*; Willatzen Morten; Albrektsen Ole; Bozhevolnyi Sergey I

来源：Journal of Computational and Theoretical Nanoscience, 2011, 8(8): 1619-1624.

DOI：10.1166/jctn.2011.1856

• Plasmonics
• Scattering
• Optical Resonances
• Quality Factor
• Multipole Expansion

We study the absorption and scattering cross sections of three-dimensional retardation-based plasmonic resonators as straight gold nanorod antennas are transformed gradually to split-ring resonators. Using a multipole expansion of the scattered field, we show by bending the nanoantennas that it is possible at the fundamental resonance to suppress the scattering due to a decrease in the electric dipole response in favor of a magnetic dipole response. The decrease in scattering strength is accompanied by an increase in the Q-factor which in the split-ring resonator limit is improved by a factor of similar to 1.9 (equivalent to similar to 1.2 times larger than the quasi-static value). Additionally, the split-ring resonator shows promising prospects in surface enhanced sensing applications with local field enhancement of >= 50 in the split-ring gap.

• 出版日期2011-8