Open AccessReflectionless zero refractive index metasurface in the terahertz waveband
Author(s) -
Takao Suzuki,
Harumi Asada
Publication year - 2020
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.395223
Subject(s) - refractive index , terahertz radiation , optics , dielectric , permittivity , materials science , relative permittivity , transmittance , metamaterial , electromagnetic radiation , relative permeability , optoelectronics , physics , porosity , composite material
Zero refractive index materials behave electromagnetically as single points despite the finite dimensions because a propagating electromagnetic wave passes with an infinite phase velocity. However, the composition of naturally occurring materials cannot produce a zero refractive index material because any effect of both of the dielectric and magnetic properties would have to vanish (be near zero). In this report, we demonstrate a zero refractive index metasurface with a refractive index of 0.16 + j0.09, the reflectance of 0.7%, and transmittance of 97.3% at 0.505 THz. The measured relative permittivity and relative permeability are 0.18 - j0.10 and 0.004 + j0.16 at 0.505 THz, respectively. Both the relative permittivity and relative permeability simultaneously approach zero at the same frequency, and the dielectric and magnetic properties appear to be absent (vanish) in the artificial material. The zero refractive index metasurface can offer a material platform for terahertz applications with unprecedented functionalities for 6G (beyond 5G) wireless communications, imaging, and security.