High-resolution surface plasmon resonance sensor based on linewidth-optimized nanohole array transmittance

A high spectral resolution, 2D nanohole-array-based surface plasmon resonance sensor that operates at normal or near normal incidence-facilitating high spatial resolution imaging-is presented. The angular and spectral transmittance of the structure is modified from a Fano type to a pure Lorentzian line shape with a parallel and orthogonal polarizer-analyzer pair. This change leads to a linewidth narrowing that maximizes the sensor resolution, which we show to be of O(10(-5)) refractive index units (RIU). We estimate the potential of this system of 0(10(-6)) RIU under optimal conditions. (c) 2006 Optical Society of America.