Dielectric Nanoantennas – Enhanced Localized Surface Plasmon Resonance for Sensing Applications

Abstract

A subwavelength bridge between free-space optical radiation and localized electromagnetic energy is formed by an optical antenna. Its geometries and material composition have a major influence on its localized electromagnetic modes. Here, the design of silicon-based plasmonic nanoantennas is proposed and numerically analyzed. In comparison to plasmonic nanoantennas, high-index dielectric nanoantennas exhibit several advantages such as CMOS compatibility and low ohmic losses that may benefit nanophotonic applications. The surrounding material affects the enhanced localized field as well as the wavelength of the enhancement peak. In this work, the dipole nanoantenna is proposed with a silicon material of large excess carrier concentrations. The enhancement occurs in the mid-IR spectral region and it is useful for sensing and biochemical applications.