[19a-H116-1~12] 3.16 Optics and Photonics English Session

▲ [19a-H116-5] Terahertz Plasmonic Waveguides based on Metallic Rod Arrays

〇Borwen You¹, Ja-Yu Lu², Toshiaki Hattori¹ (1.Univ. of Tsukuba, Japan, 2.NCKU, Taiwan)

Keywords:terahertz waveguide, terahertz metamaterial

Surface plasmon polaritons (SPPs) of metals should be excited by the photons with electromagnetic (EM) frequencies from the UV to the near IR, which is far away from those of the terahertz (THz) photons. Based on the definition of dielectric constants, semiconductors are critical and well developed to generate THz–SPPs. However, to control THz–SPPs, the integration of periodic structures with the semiconductors is becoming crucial, such as the phase–matching criteria to couple the EM–waves and the surface–guiding criteria with high confinement. Comparing to the semiconductor materials, spoof–THz–SPPs are also theoretically demonstrated in structured metal surfaces with the subwavelength–scaled periods, and the structure depth instead of the carrier concentration to dominate the field confinement is approved. THz plasmonic waveguides based on the aforementioned surface waves certainly suffers the serious dispersion, attenuation, delocalized waveguide modes and the special incident angles to couple THz–EM waves. The micro–fabrication of high–aspect ratio for the surface structures on semiconductors and general metals is perplexed; especially the structure length/depth should be millimeter level. It is not easy to prepare in chemical or mechanical machining processes. To improve those disadvantages for developing chip–based spectrometers and lab–chip sensors based on THz plasmonics, this presentation demonstrates an edge–coupled plasmonic THz waveguide using the metal rods.