372048.fig.004a
(a)
372048.fig.004b
(b)
372048.fig.004c
(c)
372048.fig.004d
(d)
Figure 4: (a) Dispersion relation of the plasmonic waveguide system of Figure 3(a) calculated using FDFD (circles) and scattering matrix theory (solid line). Results are shown for 𝐿 1 = 3 6 0  nm, 𝐿 2 = 1 6 0  nm (black line and circles) and 𝐿 1 = 2 9 5  nm, 𝐿 2 = 2 2 0  nm (red line and circles). All other parameters are as in Figure 3(b). In both cases only a portion of the band structure is shown, corresponding to the frequency range of the middle band. ((b)-(c)) Reciprocal of the group velocity 𝑣 𝑔 and propagation length 𝐿 𝑝 for the plasmonic waveguide system of Figure 3(a) as a function of frequency calculated using FDFD. Results are shown for 𝐿 1 = 3 6 0  nm, 𝐿 2 = 1 6 0  nm and 𝐿 1 = 2 9 5  nm, 𝐿 2 = 2 2 0  nm. All other parameters are as in Figure 3(b). (d) Dispersion relation of the plasmonic waveguide system of Figure 3(a) calculated using FDFD. Results are shown for 𝑑 = 1 0 0  nm (black line), 𝑑 = 2 0 0  nm (red line), and 𝑑 = 3 0 0  nm (green line). All other parameters are as in Figure 3(b). In all cases only a portion of the band structure is shown, corresponding to the frequency range of the middle band.