Nano-antenna for optical resolution using plasmonic material as substrate

In this paper, the concept to enhanced directivity of a electrically small subwavelength radiator containing plasmonic materials with negative permittivity at THz, infrared and optical frequencies have been explored theoretically. We study plasmonic resonances of a subwavelength core-shell spherical nanoantenna and simulate the far-field radiation patterns of such a structure when it is excited by a small dipole source. The size, shape and material of the nanoantenna determine the antenna response.