Fig. 9.

External plasmonic vortex nanogear transmissions. (a) Schematic of a linear chain of Ag nanoparticle dimers (r=50nm, d_x=10nm, d_y=3nm, ambient index n=1.33). Wavelength spectra of the electric field intensity enhancement in the gap of the central dimer (b), the far-field scattering and absorption efficiencies (c), the Poynting vector amplitude (d) and the phase of the Poynting vector in the x-z plane (e) in the gap of the central dimer of the nanostructures composed of three (solid blue lines) and five (solid red lines) nanodimers. The corresponding spectra of a single dimer are shown as dashed grey lines. The structures are illuminated by a plane wave with the electric field polarized along the dimers axes. Electric field intensity distribution in the gaps of a single dimer (f), three-dimer chain T₁ (g), and five-dimer chain T₂ (h). Poynting vector intensity distribution and powerflow through the gaps of the dimer (i), T₁ (j) and T₂ (l). Schematics of the VNTs generated in T₁ (k) and T₂ (m) at their resonant wavelengths. Light flux in each nanogear is looped between the particles.