Abstract

Surface plasmon resonance (SPR) has been widely used in sensors because of its high sensitivity to refractive index change of the surrounding materials. Recently, much attention has been placed on metallic nanoslit array sensors by using various mechanisms such as Fano-resonance and extraordinary optical transmission because they allow SPR at normal incidence which can be used for miniaturization of plasmonic sensors [1]. The sensing performance of nanoslit-array-based SPR sensors are often quantified by the sensitivity (S) and the figure of merit (FOM). These parameters are highly dependent on the dielectric constant of slab material (ε_m = ε_r + iε_i). When |ε_r| and |ε_i| decrease, sensitivity and FOM increase respectively [2]. Such reduction of effective dielectric constant of the slab can be achieved by replacing the conventional metal nanoslit array into the proposed double-side metal-coated dielectric nanoslit array.

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