Abstract

Single molecule detection via surface-enhanced Raman scattering (SERS) technique with the help of enhanced electromagnetic field near the metallic nanostructure has attracted much attention recently. A large electric field enhancement can be produced in the gap of a bowtie-shaped antenna by exciting the localized surface plasmon resonance (LSPR) [1]. Also, core-shell particles, tunable plas-monic spheres consist of multilayer metallic shells, have been studied widely due to the extraordinary sensing abilities [2]. However, there are few works on the advantage of combining the enhanced electric field in bowtie antenna gap with the great sensitivity of core-shell structure. The purpose of this work is to perform simulations on a model system of contour bowtie antenna to investigate the critical dimension to induce the additional enhancement by examining the resonance wavelength and the local electromagnetic field enhancement dependence on bowtie size and contour thickness. In addition, a plasmon hybridization model was proposed to explain the simulation results.

© 2015 Japan Society of Applied Physics, Optical Society of America