An electromagnetic multipole expansion beyond the long-wavelength approximation

By R. Alaee, Carsten Rockstuhl, I. Fernandez‐Corbaton. 2017

410 citations recorded by the source corpus.

Abstract The multipole expansion is a key tool in the study of light–matter interactions. All the information about the radiation of and coupling to electromagnetic fields of a given charge-density distribution is condensed into few numbers: The multipole moments of the source. These numbers are frequently computed with expressions obtained after the long-wavelength approximation. Here, we derive exact expressions for the multipole moments of dynamic sources that resemble in their simplicity their approximate counterparts. We validate our new expressions against analytical results for a spherical source, and then use them to calculate the induced moments for some selected sources with a non-trivial shape. The comparison of the results to those obtained with approximate expressions shows a considerable disagreement even for sources of subwavelength size. Our expressions are relevant for any scientific area dealing with the interaction between the electromagnetic field and material systems.

Subfields: Atomic and Molecular Physics, and Optics, Biomedical Engineering, Civil and Structural Engineering

View Paper: https://www.semanticscholar.org/paper/faac6d6562c3492a39dc4482b3a46c0fd32168c8

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Atomic and Molecular Physics, and Optics

1. Carsten Rockstuhl
2. M. Albooyeh
3. R. Alaee

In Biomedical Engineering

1. Carsten Rockstuhl
2. M. Albooyeh
3. R. Alaee

Citations in the corpus

• Theory of metasurface based perfect absorbers (2017, background): “Note that by using induced electric current, it is easy to show that the considered nanopatch antenna only supports an electric dipole moment [34].”