title: Nanofocusing of terahertz wave in a tapered hyperbolic metal waveguide.
abstract: An tapered hyperbolic metal waveguide is suggested for the nanofocusing of terahertz waves. We numerically show that, at the frequency of 1 THz, the focal spot can be as small as only 5 nm, which is smaller than that of a plate waveguide by 2 orders of magnitude. Correspondingly, the longitudinal component of the energy flow density is stronger than that of a plate waveguide by 3 orders of magnitude for the same input. It is shown that these significant improvements come from the small imaginary part of the effective index of the hyperbolic metal waveguide.
authors.forename: Hua
authors.initials: H
authors.lastname: Gao
authors.forename: Qing
authors.initials: Q
authors.lastname: Cao
authors.forename: Minning
authors.initials: M
authors.lastname: Zhu
authors.forename: Da
authors.initials: D
authors.lastname: Teng
authors.forename: Siyi
authors.initials: S
authors.lastname: Shen
mesh_terms: D003198:Computer Simulation; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008962:Models, Theoretical; D036103:Nanotechnology / Q000295:instrumentation*; D012542:Scattering, Radiation; D020349:Surface Plasmon Resonance / Q000295:instrumentation*; D055053:Terahertz Radiation