Figure 2.

Cross-sectional view of the simulated electric field intensity ${\left|E\right|}^2$ and magnetic field intensity ${\left|H\right|}^2$ at resonant wavelengths of ${\lambda }_{R1}=653$ nm (a,c) and ${\lambda }_{R2}=865$ nm (b,d), respectively. Electric field intensity at both resonant wavelengths is enhanced by a factor of up to ${10}^3$, around the edges of the nanodisc. This confirms that the first resonant mode is excited with incident light coupling into the propagating surface plasmons (PSPs) on the gold film. On the other hand the second resonant mode is a fundamental LSP.