Toroidal dipole and magnetic multipole excitations from the same nanostructure with different direction of electric dipole emitters

Abstract

The toroidal dipole (TD) and magnetic multipole with optical response from high-index dielectric nanostructures are emerging optical nanostructures especially in the visible spectrum. However, interference of the involved multipoles is generally overlooked in the ultraviolet region. In this work, a novel nanostructure which can achieve excitations of TD, magnetic quadrupole and magnetic dipole is demonstrated by simply changing the direction of the electric dipole emitters in the wavelength range between 230 and 430 nm. Near perfect TD and magnetic excitations from the same structure are accomplished and our results also provide insights into the design and application of light nanoantennas, spectroscopy, and ultrafast light emitting devices.