Index matching of surface plasmons

摘要

We have measured the angle and wavelength dependent transmission of index matched metal hole arrays, and of arrays with a dielectric pillar in each hole. Index matching enhances the transmission, but also broadens the resonances due to an enhanced coupling between plasmon and radiation modes. Hole arrays that are covered with glass or have a glass pillar in each hole are created using an imprinting technique. We observe additional waveguide modes in the transmission spectra of these arrays and discuss the avoided crossing that we observe for the hybrid structure with dielectric pillars in the holes.