Sharp resonances in waveguide-coupled surface plasmon sensors for super-resolution sensing

Abstract

In conventional surface plasmon resonance (SPR) sensors, an Au single layer is commonly used, but the resolution is limited by the broad SPR for the Au layer. Attempts to get sharper resonances have been made using various structures including long range SPRs [1] and waveguide-coupled SPRs [2]. In waveguide-coupled SPR sensors, the waveguide structure is integrated in the SPR sensor. Sharp resonances have been achieved for both the p- and s-polarized incident light upon excitation of waveguide modes (WGM). However, coupling between SPP and WGM has not been achieved in the sensor structures proposed so far.