Abstract:
The internal field patterns for gold shells filled with the same material as the surrounding medium are calculated
with Mie theory and in the quasistatic approximation and their properties compared to the response of
homogeneous spheres and metallic rings. One major difference between the sphere and shell case is that the
areas of highest field enhancement in metallic shells are located perpendicular to the incident polarization,
whereas for metallic spheres they are along the polarization direction. Recent results based on the discrete
dipole approximation (DDA) are shown to be misleading, which might be due to the use of a too coarse grid
size. We also show that the type of resonance and the associated internal field pattern (low or high energy)
has a strong impact on the external fields.
