Abstract

The resonant oscillation of the conduction electrons excited by light interacting with a sub-wavelength metallic nanostructure is called localized surface plasmon resonance (LSPR). It has been shown that a large electromagnetic field can be excited in the gap of a bowtie-shaped nanoantenna [1]. Also, investigations of nanoring structures have exhibited better electric field enhancement and sensitivity compared to solid nanodisk structures [2]. However, there are few reports on the advantages of combining the great electromagnetic field enhancement produced in the bow-tie-shaped antenna gap with the enhanced sensitivity characteristic of the nanoring structure. The purpose of the present work is to perform numerical studies on a model system of bowtie nanoring antenna array to examine the dependence of resonance wavelength, local electromagnetic field enhancement, and sensitivity on the nanohole size inside the bowtie nanoring antenna.

© 2014 Japan Society of Applied Physics, Optical Society of America