Metrological performance of integrated waveguide-based SPR refractometer: eigenmode expansion perspective

The waveguide-based SPR refractometer is studied using state-of-the-art photonic simulation software based on eigenmode expansion method. Two distinct coupling regimes between the waveguide mode and surface plasmon mode are identified. Operating the refractometer in different spectral ranges to measure different values of the ambient refractive index is considered and its metrological performance under different modes of operation is assessed.