Engineering optical response through gold bowtie nanoantennas array

We propose the coupled gold bowtie nanoantennas array and investigate its plasmonic properties theoretically. The bowtie antenna consists of a pair of opposing truncated cones. We calculate the transmission spectra and the electric field distributions. The evolution of the transmission spectrum with the gap width of the bowtie, the diameter of the tip of the cone and the distance between adjacent bowties is directly visualized. Furthermore, the sensitivity of the antennas array to dielectric constant changes of the environment is also investigated in detail. We show the electric field distribution of this nanostructure and find that Ex is mainly located at the corners of the cross section, especially at the extremity of the cone. As for the Ey, the electric field enhancement localizes at the external edges and the gap of the bowtie. Our work elucidates further the plasmonic interactions can be useful in the design of optimized, sensitive optical sensors, and the enhancement of the fluorescence of molecules.

Research highlights
► This paper proposes the coupled gold bowtie nanoantennas array.
► The transmission spectra are directly visualized with geometrical parameters.
► The sensitivity of the antennas array to local environment is also investigated.
► Ex is mainly located at the corners, especially at the extremity of the cone.
► Ey localizes at the external edges and the gap of the bowtie.