Abstract
We study the diffraction of electromagnetic waves from subwavelength metallic circular apertures in the microwave spectrum. The theoretical and experimental demonstration of the near- and far-field electromagnetic distributions for subwavelength circular annular apertures and circular annular apertures surrounded by concentric periodic grooves are reported here. The metallic samples had a subwavelength hole with a diameter of 8 mm and had concentric grooves with a periodicity of 16 mm. We present the angular transmission distributions from circular annular apertures, and circular annular apertures surrounded by concentric periodic grooves. At the surface-mode resonance frequency the transmitted electromagnetic waves from the subwavelength circular annular aperture surrounded by concentric periodic grooves have a strong angular confinement with an angular divergence of ±3°. This represents a fourfold reduction when compared with the angular divergence of the beam transmitted from the subwavelength circular aperture.
| Original language | English |
|---|---|
| Pages (from-to) | 419-422 |
| Number of pages | 4 |
| Journal | Journal of the Optical Society of America B: Optical Physics |
| Volume | 23 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - Mar 2006 |
| Externally published | Yes |
| Publication type | A1 Journal article-refereed |
ASJC Scopus subject areas
- Statistical and Nonlinear Physics
- Atomic and Molecular Physics, and Optics