Abstract
We investigate a one-dimensional plasmonic crystal using momentum-resolved electron energy-loss spectroscopy (EELS) and cathodoluminescence (CL) techniques, which are complementary in terms of available optical information. The plasmonic crystal sample is fabricated from large aluminum grains through the focused ion beam method. This approach allows curving nanostructures with high crystallinity, providing platforms for detailed analysis of plasmonic nanostructures using both EELS and CL. The momentum-resolved EELS visualizes dispersion curves outside the light cone, confirming the existence of the surface plasmon polaritons and local modes, while the momentum-resolved CL mapping analysis identified these surface plasmon polaritons and local modes. Such synergetic approach of two electron-beam techniques offers full insights into both radiative and non-radiative optical properties in plasmonic or photonic structures.