Broadband Plasmonic Nanoantenna for Magnetic Field Enhancement

Abstract

We propose and analyze a type of broadband plasmonic nanoantenna capable of localizing and enhancing magnetic field at several wavelengths over a large spectral band, which is formed by three or four metallic nanowires with a common junction. We demonstrate that the properties of the nanoantenna, such as the broadband spectral response and magnetic intensity enhancement, can be tailored by engineering the geometric parameters or varying the ellipticity of the elliptically polarization. Multi-wavelength operation of the plasmonic nanoantenna provides tremendous opportunities for broadband magnetic field imaging and magnetic-optic modulation of plasmon polaritons at near-infrared frequencies.