One-way quasiplanar terahertz absorbers using nonstructured polar dielectric layers
Fecha
2017Versión
Acceso abierto / Sarbide irekia
Tipo
Artículo / Artikulua
Versión
Versión publicada / Argitaratu den bertsioa
Impacto
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10.1103/PhysRevB.96.155148
Resumen
A concept of quasiplanar one-way transparent terahertz absorbers made of linear isotropic materials is presented. The resulting structure consists of a homogeneous absorbing layer of polar dielectric, GaAs, a dispersion-free substrate, and an ultrathin frequency-selective reflector. It is demonstrated that perfect absorption can be obtained for forward illumination, along with total reflection at ...
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A concept of quasiplanar one-way transparent terahertz absorbers made of linear isotropic materials is presented. The resulting structure consists of a homogeneous absorbing layer of polar dielectric, GaAs, a dispersion-free substrate, and an ultrathin frequency-selective reflector. It is demonstrated that perfect absorption can be obtained for forward illumination, along with total reflection at backward illumination and transparency windows in the adjacent bands. The design is particularized for the polaritonic gap range where permittivity of GaAs varies in a wide range and includes epsilon-near-zero and transparency regimes. The underlying physics can be explained with the aid of a unified equivalent-circuit (EC) analytical model. Perfect matching of input impedance in forward operation and, simultaneously, strong mismatch in the backward case are the universal criteria of one-way absorption. It is shown that perfect one-way absorption can be achieved at rather arbitrary permittivity values, provided these criteria are fulfilled. The EC results are in good agreement with full-wave simulations in a wide range of material and geometrical parameters. The resulting one-way absorbers are very compact and geometrically simple, and enable transparency in the neighboring frequency ranges and, hence, multifunctionality that utilizes both absorption- and transmission-related regimes. [--]
Materias
One-way quasiplanar terahertz absorbers,
Nonstructured polar dielectric layers
Editor
American Physical Society
Publicado en
Physical Review B
96, 155148 (2017)
Departamento
Universidad Pública de Navarra. Departamento de Ingeniería Eléctrica y Electrónica /
Nafarroako Unibertsitate Publikoa. Ingeniaritza Elektrikoa eta Elektronikoa Saila
Versión del editor
Entidades Financiadoras
This work is supported by the Spanish Ministerio de
Economía y Competitividad (MINECO) (TEC2014-51902-
C2-2-R). P.R.U. is sponsored by the Public University of
Navarra via a predoctoral scholarship, and A.E.S. is sup-
ported by the National Science Center of Poland (NCN)
(MetaSel DEC-2015/17/B/ST3/00118). We are very thankful
to Prof. S. Nojima, YCU (Yokohama, Japan), for valuable
discussions.