Local surface plasmon resonance mode (LSPR) mapping of gold pyramids using cathodoluminescence. (a) Composite image of secondary electron image (gray) and, 650 nm (green) and 750 nm (red) monochromatic cathodoluminescence images. (b) Cathodoluminescence spectra from edge and apex of the pyramid in the center of image (a). LSPRs at apex and edges of pyramid are revealed to be 670 nm (1.85 eV) and 620 nm (2.0 eV) emissions, respectively. Acquisition time 2 s/spectrum.
