Figure 6

Experimentally recorded Fourier images of hexagonal gold nanoplates.
(a) The bright field image in the real image plane of the hexagonal gold nanoplate with labelled edges (1, 2 and 3). The red arrow represents the polarization of incident light. (b) The dark field images in the real image plane of SPP corner modes propagating along three labelled edges. (c) The Fourier image of propagating SPP modes in all different directions under the polarization state in (a). By adjusting the polarization of incident light, the Fourier images correspond to intensity peaks of the three propagation directions (kx1, kx2 and kx3) are shown in (d) to (f). By extracting the propagating leaky SPP corner mode in one direction (kx1, kx2 or kx3) in the real image plane, the corresponding Fourier images are shown in (g) to (i).