Simulate the optical response of a plasmonic resonance. Adaptive FEM mesh ensures high accuracy.

Fig. 1: Geometry. 64nm wide gold wire with a 6nm deep groove. (Mirror symmetry at the center plane applied.)

Plasmonic antennas have been proposed for applications like, e.g., ultra-sensitive bio-sensing. When a plasmonic resonator includes a small geometrical feature like a tiny V-groove, the local field intensities of the electromagnetic field can be enhanced by several orders of magnitude. However, the accurate simulation of such field enhancements can be numericallly challenging.
We use adaptive finite elements for the efficient simulation of a V-groove antenna.
FEM Mesh (JCMgeo)



Fig. 2: Detail of the finite element mesh. Figure 1 shows a typical geometry of a V-groove antenna. The geometry is invariant in the third spatial dimension. A monochromatic light field is incident from the top. Figure 2 shows the FEM mesh created by JCMgeo. Figure 3 shows the wavelength-dependent local field enhancement. A typical electromagnetic field intensity distribution is shown in Figure 4.







Fig. 3: Wavelength dependent response of the resonating structure.


Fig. 4: Pseudo color plot of the light intensity distribution of an illuminated plasmonic V-groove antenna. Computation time roughly one second on a standard PC. Relative accuracy (numerical error) of the local field enhancement on resonance better 1%.

C. Hafner et al. - Paper on frequency-domain simulations of optical antenna structures including a description of V-groove antennas.

J. Smajic et al. - Paper comparing FEM, FDTD, MMP, BE methods for plasmonic structures, including a V-groove antenna.

Hoffmann et al. - Comparison of electromagnetic field solvers for the 3D analysis of plasmonic nanoantennas