Abstract
We demonstrate that optical transmission of a normally incident, monochromatic plane wave through a single sub-wavelength aperture in an opaque metal film can be substantially enhanced by a thin, semitransparent metal film placed parallel to the opaque metal film in front of the aperture. When the semi-transparent and the opaque metal film are separated by a proper distance, a light trapping cavity is formed and the sub-wavelength aperture exhibits a transmission maximum. An enhancement factor of ~40 is demonstrated for a cylindrical 100 nm diameter hole in a silver film.
| Original language | English |
|---|---|
| Pages (from-to) | 23992-24001 |
| Number of pages | 10 |
| Journal | Optics Express |
| Volume | 17 |
| Issue number | 26 |
| DOIs | |
| Publication status | Published - 2009 |
| MoE publication type | A1 Journal article-refereed |