Abstract

Periodic bowtie nanoantenna arrays fabricated by e-beam lithography have demonstrated large electric field enhancement at hotspots due to the coupling between two nanoprisms, and they have been used as effective substrates for surface-enhanced Raman scattering and localized surface plasmon resonance-based biosensing. Their plasmon oscillation has also been shown to be sensitive to the local dielectric environment, which can be modified through different gap sizes between opposing tips [1], geometrical changes of bowtie nanoantenna [2], etc. The effects of in-plane symmetric rotation of bowtie with respect to its opposing tips on the electric field enhancement and spectral response are studied in the present work to examine the influence of rotation angle on the resonance behaviors. Due to the sensitive nature of the bowtie nanostructure, different couplings between the two nanoprisms of bowtie at different rotation angles would lead to both the shift in resonance wavelength and the emergence of new resonance modes.

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