Figure 3: Uncovering the near-field dynamics of an arc-shaped structure-free plasmon lens.
From: Mapping plasmonic near-field profiles and interferences by surface-enhanced Raman scattering
(a) Schematic illustration of the lens produced from focusing an arc-shaped RPB segment defined by expanding angle θ. SPPs from the lens propagate radially towards to the center, forming a plasmonic focal spot. (b)–(d) Experimentally measured (purple-white) and calculated (red-white) plasmon fields at the metal surface under expanding angles 90°, 120°, and 180°, respectively, showing strong matches. Area of each contour map is 8 μm×8 μm.
