Letter abstract
Nature Photonics 3, 152 - 156 (2009)
Published online: 22 February 2009 | doi:10.1038/nphoton.2009.22
Subject Category: Terahertz optics
Terahertz field enhancement by a metallic nano slit operating beyond the skin-depth limit
M. A. Seo1, H. R. Park1, S. M. Koo2, D. J. Park1, J. H. Kang3, O. K. Suwal4, S. S. Choi4, P. C. M. Planken5, G. S. Park1, N. K. Park2, Q. H. Park3 & D. S. Kim1
Abstract
The unique optical properties of metals are at the core of many areas of research and applications, including plasmonics1, 2, 3, 4, metamaterials5, 6, superlensing and subdiffraction focusing7, 8, 9, 10, optical antennas11, 12, 13, 14 and surface enhanced Raman scattering15. One important length scale inherent in metamaterials and plasmonics research activities in the microwave5, 16, terahertz17, 18, 19, infrared20, 21, visible22 and ultraviolet ranges7 is the skin depth of metal, which remains at the submicrometre level throughout the broad spectral range. One prominent question is whether terahertz electromagnetic waves can be controlled on the nanoscale to achieve new functionalities in the sub-skin-depth regime. Here, we show that a 
/30,000 slit on metal film acts as a nanogap-capacitor charged by light-induced currents, enhancing the electric field by orders of magnitudes.
- Center for Subwavelength Optics and Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea
- Photonic Systems Laboratory, School of EECS, Seoul National University, Seoul 151-744, Korea
- Department of Physics, Korea University, Seoul 136-701, Korea
- Department of Physics and Advanced Materials Science, Sun Moon University, Asan 336-708, Korea
- Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
Correspondence to: D. S. Kim1 e-mail: dsk@phya.snu.ac.kr
Correspondence to: Q. H. Park3 e-mail: qpark@korea.ac.kr
