Abstract-Broadband and energy-concentrating terahertz coherent perfect absorber based on a self-complementary metasurface

Yoshiro Urade, Yosuke Nakata, Toshihiro Nakanishi, and Masao Kitano

https://www.osapublishing.org/ol/abstract.cfm?uri=ol-41-19-4472

We demonstrate that a self-complementary checkerboard-like metasurface works as a broadband coherent perfect absorber (CPA) when symmetrically illuminated by two counter-propagating incident waves. A theoretical analysis based on wave interference and the results of numerical simulations of the proposed metasurface are provided. In addition, we experimentally demonstrate the proposed CPA in the terahertz regime by using a time-domain spectroscopy technique. We observe that the metasurface can work as a CPA below its lowest diffraction frequency. The size of the absorptive areas of the proposed CPA can be much smaller than the incident wavelength. Unlike conventional CPAs, the presented one simultaneously achieves the broadband operation and energy concentration of electromagnetic waves at the deep-subwavelength scale.

© 2016 Optical Society of America

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Abstract-Dynamically Babinet-invertible metasurface: a capacitive-inductive reconfigurable filter for terahertz waves using vanadium-dioxide metal-insulator transition

Yoshiro Urade, Yosuke Nakata, Kunio Okimura, Toshihiro Nakanishi, Fumiaki Miyamaru, Mitsuo W. Takeda, Masao Kitano

(Submitted on 24 Feb 2016)

https://www.blogger.com/blogger.g?blogID=124073320791841682&pli=1#editor/target=post;postID=2197810776175091966

This paper proposes a reconfigurable planar metamaterial that can be switched between capacitive and inductive responses using local changes in the electrical conductivity of its constituent material. The proposed device is based on Babinet's principle and exploits the singular electromagnetic responses of metallic checkerboard structures, which are dependent on the local electrical conductivity. Utilizing the heating-induced metal-insulator transition of vanadium dioxide (VO2), the proposed metamaterial is designed to compensate for the effect of the substrate and is experimentally characterized in the terahertz regime. This reconfigurable metamaterial can be utilized as a switchable filter and as a switchable phase shifter for terahertz waves.

Abstract-Dynamically Babinet-invertible metasurface: a capacitive-inductive reconfigurable filter for terahertz waves using vanadium-dioxide metal-insulator transition

Yoshiro Urade, Yosuke Nakata, Kunio Okimura, Toshihiro Nakanishi, Fumiaki Miyamaru, Mitsuo W. Takeda, and Masao Kitano

https://www.osapublishing.org/oe/abstract.cfm?uri=oe-24-5-4405

This paper proposes a reconfigurable planar metamaterial that can be switched between capacitive and inductive responses using local changes in the electrical conductivity of its constituent material. The proposed device is based on Babinet’s principle and exploits the singular electromagnetic responses of metallic checkerboard structures, which are dependent on the local electrical conductivity. Utilizing the heating-induced metal-insulator transition of vanadium dioxide (VO2), the proposed meta-material is designed to compensate for the effect of the substrate and is experimentally characterized in the terahertz regime. This reconfigurable metamaterial can be utilized as a switchable filter and as a switchable phase shifter for terahertz waves.

© 2016 Optical Society of America

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