All-dielectric carpet cloaks with three-dimensional anisotropy control

In this article, we propose all-dielectric carpet cloaks composed of jungle gym shaped dielectric unit cells and present a design strategy for three-dimensional (3-D) anisotropy control based on the transformation optics. The carpet cloaks are 3-D printable and operate with polarization independent...

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Main Authors: Maegawa Yuki, Nakata Yosuke, Sanada Atsushi
Format: Article
Language:English
Published: De Gruyter 2023-06-01
Series:Nanophotonics
Subjects:
Online Access:https://doi.org/10.1515/nanoph-2022-0786
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author Maegawa Yuki
Nakata Yosuke
Sanada Atsushi
author_facet Maegawa Yuki
Nakata Yosuke
Sanada Atsushi
author_sort Maegawa Yuki
collection DOAJ
description In this article, we propose all-dielectric carpet cloaks composed of jungle gym shaped dielectric unit cells and present a design strategy for three-dimensional (3-D) anisotropy control based on the transformation optics. The carpet cloaks are 3-D printable and operate with polarization independent incident waves in arbitrary incident angles due to the 3-D anisotropy control. Realizable anisotropic permittivities of cubic and rectangular unit cells are numerically studied based on the relative permittivity and loss tangent of ɛ r = 2.9 and tan δ = 0.02 of ultra-violet curing resin measured at the microwave frequency. It is shown that the unit cell has little frequency dependence even with the anisotropy in the low frequency range where the effective medium approximation is valid. A carpet cloak is designed based on the design method with a quasi-conformal coordinate transformation and implemented with the unit cells taking into account its realizable anisotropy. Polarization independent 3-D cloaking operations of the designed cloak are confirmed numerically. The designed cloak is fabricated by stereolithography 3-D printing technology and its cloaking performances are evaluated experimentally at 10 GHz. It is shown that non-specular reflections are well suppressed by the carpet cloak for both TE and TM incident waves with different incident angles of 30, 45, and 60°. Frequency independent cloaking operations are also shown experimentally in the X-band. The measured near-field distributions and bistatic radar cross sections are in good agreement with simulated predictions and the validity of the design method is confirmed.
format Article
id doaj-art-14f5b964686449b1adc3e11c68c848eb
institution Kabale University
issn 2192-8614
language English
publishDate 2023-06-01
publisher De Gruyter
record_format Article
series Nanophotonics
spelling doaj-art-14f5b964686449b1adc3e11c68c848eb2025-02-02T15:46:12ZengDe GruyterNanophotonics2192-86142023-06-0112132623263610.1515/nanoph-2022-0786All-dielectric carpet cloaks with three-dimensional anisotropy controlMaegawa Yuki0Nakata Yosuke1Sanada Atsushi2Graduate School of Engineering Science, Osaka University, Toyonaka, JapanGraduate School of Engineering Science, Osaka University, Toyonaka, JapanGraduate School of Engineering Science, Osaka University, Toyonaka, JapanIn this article, we propose all-dielectric carpet cloaks composed of jungle gym shaped dielectric unit cells and present a design strategy for three-dimensional (3-D) anisotropy control based on the transformation optics. The carpet cloaks are 3-D printable and operate with polarization independent incident waves in arbitrary incident angles due to the 3-D anisotropy control. Realizable anisotropic permittivities of cubic and rectangular unit cells are numerically studied based on the relative permittivity and loss tangent of ɛ r = 2.9 and tan δ = 0.02 of ultra-violet curing resin measured at the microwave frequency. It is shown that the unit cell has little frequency dependence even with the anisotropy in the low frequency range where the effective medium approximation is valid. A carpet cloak is designed based on the design method with a quasi-conformal coordinate transformation and implemented with the unit cells taking into account its realizable anisotropy. Polarization independent 3-D cloaking operations of the designed cloak are confirmed numerically. The designed cloak is fabricated by stereolithography 3-D printing technology and its cloaking performances are evaluated experimentally at 10 GHz. It is shown that non-specular reflections are well suppressed by the carpet cloak for both TE and TM incident waves with different incident angles of 30, 45, and 60°. Frequency independent cloaking operations are also shown experimentally in the X-band. The measured near-field distributions and bistatic radar cross sections are in good agreement with simulated predictions and the validity of the design method is confirmed.https://doi.org/10.1515/nanoph-2022-0786anisotropy controlcarpet cloaksinvisibility cloaksmetamaterialstransformation optics
spellingShingle Maegawa Yuki
Nakata Yosuke
Sanada Atsushi
All-dielectric carpet cloaks with three-dimensional anisotropy control
Nanophotonics
anisotropy control
carpet cloaks
invisibility cloaks
metamaterials
transformation optics
title All-dielectric carpet cloaks with three-dimensional anisotropy control
title_full All-dielectric carpet cloaks with three-dimensional anisotropy control
title_fullStr All-dielectric carpet cloaks with three-dimensional anisotropy control
title_full_unstemmed All-dielectric carpet cloaks with three-dimensional anisotropy control
title_short All-dielectric carpet cloaks with three-dimensional anisotropy control
title_sort all dielectric carpet cloaks with three dimensional anisotropy control
topic anisotropy control
carpet cloaks
invisibility cloaks
metamaterials
transformation optics
url https://doi.org/10.1515/nanoph-2022-0786
work_keys_str_mv AT maegawayuki alldielectriccarpetcloakswiththreedimensionalanisotropycontrol
AT nakatayosuke alldielectriccarpetcloakswiththreedimensionalanisotropycontrol
AT sanadaatsushi alldielectriccarpetcloakswiththreedimensionalanisotropycontrol