High Sensitivity Dark Mode Plasmonic Resonance of Gold Nanoantennas Arrays in Evanescent Waves

Abstract

Plasmonic dark modes of gold nanoantennas are observed in evanescent waves. Comparing with the bright mode for normal incidence of nanoantennas, dark mode resonance not only has a higher extinction coefficient but also achieves higher sensitivity to the surrounding environment. The sensitivity of the dark mode of gold nanoantenna is 4.84 times that of the bright mode in terms of the figure of merit.