Bragg reflection of terahertz waves in plasmonic crystals

Division of Electrical and Electronics Engineering, Korea Maritime University, Busan 606-791, Korea.
Optics Express (Impact Factor: 3.49). 06/2009; 17(11):9212-8. DOI: 10.1364/OE.17.009212
Source: PubMed

ABSTRACT

We present experimental and theoretical studies on terahertz surface plasmon (TSP) propagation on slit and rectangular aperture arrays in an aluminum sheet. Terahertz waves are coupled onto the plasmonic structures via a parallel plate waveguide. Long-lasting oscillations are observed in the temporal pulse shape after propagating through the periodic structure, whose Fourier transformation into the frequency domain results in Bragg-resonance spectral features. We show that the interference between the incident wave and the radiation reflected from both the aperture array and the waveguide block is responsible for this Bragg-resonance behavior. The reflection coefficient for a single slit is deduced to be 0.017 +/- 0.002.

Download full-text

Full-text

Available from: Antonio I. Fernández-Domínguez
  • [Show abstract] [Hide abstract]
    ABSTRACT: This presentation will give an overview of the THz metal waveguides which are single metal wire, copper coaxial cable, parallel-plate, and aluminum sheet. We investigated the propagation of single- and multi-mode terahertz (THz) radiation through a parallel-plate waveguide (PPWG) for various gap sizes of the plates and polarizations of the incoming THz field. Also we present experimental and theoretical studies on terahertz surface plasmon (TSP) propagation on slit and rectangular aperture arrays in an aluminum sheet via a PPWG. Long-lasting oscillations are observed in the temporal pulse shape after propagating through the periodic structure. We show that the interference between the incident wave and reflected wave, which is from the aperture array and the waveguide block, is responsible for the Bragg-resonance behavior.
    No preview · Article · Jan 2009
  • [Show abstract] [Hide abstract]
    ABSTRACT: This research reports an experimental and simulation study of a silicon-lens-free tapered parallel-plate waveguide (TPPWG) to improve THz coupling to the plate separation gap. The TPPWG without any silicon lens is compared to the parallel-plate waveguide (PPWG) with a plano-cylindrical silicon lens. It was found that the input- and output-side TPPWG with a 3° tapered slop angle increased by about 103% at 1 THz compared to the PPWG.
    No preview · Article · Jan 2010
  • [Show abstract] [Hide abstract]
    ABSTRACT: This paper reports an experimental and simulation study of a tapered parallel-plate waveguide (TPPWG) to improve THz coupling to the plate separation gap. The flat- and round-type TPPWG without any silicon lens is compared to the parallel-plate waveguide (PPWG) with a plano-cylindrical silicon lens. The spectrum amplitudes of the input-side TPPWG and the input- and output-side TPPWG both having a 3 degrees slop angle increased about 56% and 103% at 1 THz when compared to that of the PPWG. Since the input- and output-side TPPWG had almost no impedance mismatch to the propagating THz wave, coupling to the waveguide could be improved twice compared with the PPWG.
    No preview · Article · Jan 2010 · Optics Express
Show more