Unidirectional scattering of Si ring-Au split ring nanoantenna excited by tightly focused azimuthally polarized beam

Unidirectional scattering of various plasmonic nanoantennas has been extensively studied, giving birth to applications such as in optical sensors, solar cells, spectroscopy and light-emitting devices. The directional magnetic nanoantenna is still unexplored, though it beneficial artificial magnetism including metamaterials, cloaking nonlinear resonance. In this work, we numerically investigate the far-field properties Si ring-Au split ring (Si R-Au SRN) excited by a tightly focused azimuthally polarized beam (APB) through using finite-difference time-domain (FDTD) method. results show that resonant peaks with different widths can be deterministically Au focusing APB. Owing plasmon hybridization effect, two modes form antibonding mode bonding SRN. At wavelength <i>λ</i>=1064 nm, destructive interference between nanostructure unidirectional transverse plane, which affected dramatically changes geometrical parameters. Furthermore, dipole source realized designed nanostructure, its directionality superior Our work provides flexible way control nano-photon structures. We expect study provide an avenue nano-light sources sensors.