Polarization and mutual coupling effects in aluminum nanoantenna arrays

This paper uses finite-difference time-domain modeling to study the impact of varying the polarization of the point source(s) on both a single aluminum dipole nanoantenna and a 2 × 2 array. Starting with the single dipole nano-antenna, this paper demonstrates the strong dependence of power enhancement and resonance on the polarization of the source by alternating between orthogonal polarization states. With each element of the array excited by a single point source, the resonance, power enhancement, and far-field radiation patterns are observed as the polarization of each source is rotated, in varying combinations. The results demonstrate that a unique far-field radiation pattern is produced for each polarization combination, which may lead to applications in subdiffraction limit imaging and quantum optics.