Terahertz pulse propagation using plasmon-polariton-like surface modes on structured conductive surfaces
ABSTRACT The dispersion relation and confinement of plasmon-polariton-like terahertz surface modes sustained by a perfectly conducting planar surface patterned with a regular lattice of holes are studied using full-field three-dimensional numerical simulations. Edge coupling and subsequent surface guiding with subwavelength vertical confinement of the frequency components below the band edge of the surface mode is demonstrated for a broadband pulse with 0.5 THz ≤f≤2 THz . Additionally, the constraints imposed by lattice constant and hole size on the creation of defect waveguides offering lateral confinement are discussed.
Article: Highly confined guiding of terahertz surface plasmon polaritons on structured metal surfaces[show abstract] [hide abstract]
ABSTRACT: Metamaterials are artificial materials with subwavelength structure1 that enable the translation of magnetic2 and electric responses3 into spectral regions not accessible through naturally occurring materials. Here, we report direct measurements of the propagation and confinement of terahertz electromagnetic surface modes tightly bound to flat plasmonic metamaterials that consist of metal surfaces decorated with two-dimensional arrays of subwavelength-periodicity pits. These modes are surface plasmon polaritons with an effective plasma frequency controlled entirely by the surface geometry4. The mode spectrum and penetration depth into air demonstrate strong wavelength-scale energy confinement to the surface below the electromagnetic band edge; this is in stark contrast to the very weak confinement found at flat metal surfaces in this spectral regime. The results are in good agreement with analytical and numerical models of surface plasmon polaritons propagating on structured perfect-conductor surfaces, and imply that plasmonic metamaterials could help miniaturize optical components or lead to improved chemical or biochemical sensors.Nature Photonics 02/2008; 2(3):175-179. · 29.28 Impact Factor
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ABSTRACT: In this paper, we analyze in detail the characteristics of surface electromagnetic modes that can propagate along a periodically corrugated, perfectly conducting wire. We show how these modes, termed spoof surface plasmon polaritons , resemble surface plasmon polaritons supported by metallic wires at optical frequencies. The important point is that the dispersion relation of spoof surface plasmon polaritons is mainly controlled by the geometry of the corrugation. This fact allows the tuning of the properties of these modes via changes in corrugation geometry. Important applications lie in high-confinement waveguiding at far-infrared and microwave frequencies, including the possibility of efficient propagation to the tip of tapered structures for focusing.IEEE Journal of Selected Topics in Quantum Electronics 01/2009; · 3.78 Impact Factor