Four-mode plasmonic structure based on a prism-grating anticrossing bandgap

摘要

We have developed a plasmonic structure based on an anticrossing bandgap prism-grating coupling technique. We observe that up to four surface plasmons can be excited simultaneously in this plasmonic structure. Initial experiments confirm that such a plasmonic structure can improve sensor performance by tuning the amplitude of the grating. From numerical simulations, we conclude that plasmon modes with equal propagation constants at a different wavelength can only be excited at different grating amplitudes of our plasmonic structure, in such a way that the increase of wavelength implies the increase of the amplitude for a fixed propagation constant.