Title :
On the Use of Group Theory in Understanding the Optical Response of a Nanoantenna
Author :
Xuezhi Zheng ; Verellen, Niels ; Vercruysse, Dries ; Volskiy, Vladimir ; Van Dorpe, Pol ; Vandenbosch, Guy A. E. ; Moshchalkov, Victor
Author_Institution :
Dept. of Electr. Eng. (ESAT-TELEMIC), KU Leuven, Leuven, Belgium
Abstract :
Symmetry holds a prominent position in defining the optical response of a nanoantenna. In this work, we harness a mathematical tool, group representation theory, combine it with the eigenmode analysis for a nanoantenna, and illustrate how the symmetry allows or forbids the energetic coupling (i.e., interference) between a nanoantenna´s eigenmodes. We do this especially using a nanobar structure and a symmetric cross structure. Further, the consequence of symmetry-breaking is illustrated by an asymmetric cross-shaped nanostructure, i.e., a strong asymmetric Fano-type resonance line shape due to mode interference is observed with the physics behind elaborated. Both numerical and experimental evidences are provided.
Keywords :
antennas; eigenvalues and eigenfunctions; group theory; integral equations; interference; nanotechnology; asymmetric cross-shaped nanostructure; eigenmode analysis; energetic coupling; group representation theory; mathematical tool; mode interference; nanoantenna eigenmodes; nanobar structure; optical response; strong asymmetric Fano-type resonance line shape; symmetry-breaking; volumetric integral equation; Abstracts; Eigenvalues and eigenfunctions; Finite element analysis; Impedance; Interference; Physics; Shape; Eigenmodes; Group Theory; Mode Interference and Fano Resonance; Nanoantennas; Symmetry/Symmetry Breaking; Volumetric Integral Equation (VIE); group theory; mode interference and Fano resonance; nanoantennas; symmetry/symmetry breaking; volumetric integral equation (VIE);
Journal_Title :
Antennas and Propagation, IEEE Transactions on
DOI :
10.1109/TAP.2015.2400471