Terahertz Fresnel-zone-plate film lens based on double-layer metamaterial phase shifter

Zhengli Han, Yuma Takida, Seigo Ohno, Hiroaki Minamide

研究成果: Conference contribution

1 被引用数 (Scopus)

抄録

We have developed a thin THz-wave planar lens based on the phase-patterned Fresnel zone plate (FZP) concept to obtain a high transmittance and short focal length in free space. The FZP lens was designed for focusing THz waves at 1.0 THz (λ=300 μm) with a transmittance of more than 80% and a focal length of 24 mm (80λ). The developed FZP lens was made of polymer BCB as a flexible film substrate with concentric zones of metamaterial-based phase shifter patterns with a subwavelength thickness of approximately 48 μm (0.16λ). To obtain the THz-wave phase retardation of i€/2 compared to the naked polymer substrate, we employed the metamaterial unit structure consisting of double-layer unsplit ring resonators (USRRs) with a 32-μm distance between the two layers. The experimental result confirms that the FZP lens creates a focus by constructive interference of incident THz waves through concentric zones of metamaterial-patterned and un-patterned regions. By using a narrowband THz-wave beam from an injection-seeded THz-wave parametric generator, the measured focus spot size of 0.57 mm at full width at half maximum was obtained at the designed frequency of 1.0 THz. Using this FZP lens, the THz-wave imaging test in transmission geometry has also been demonstrated.

本文言語English
ホスト出版物のタイトルTerahertz Photonics
編集者Mona Jarrahi, Sascha Preu, Dmitry Turchinovich
出版社SPIE
ISBN(電子版)9781510634688
DOI
出版ステータスPublished - 2020
イベントTerahertz Photonics 2020 - none, France
継続期間: 2020 4月 62020 4月 10

出版物シリーズ

名前Proceedings of SPIE - The International Society for Optical Engineering
11348
ISSN(印刷版)0277-786X
ISSN(電子版)1996-756X

Conference

ConferenceTerahertz Photonics 2020
国/地域France
Citynone
Period20/4/620/4/10

ASJC Scopus subject areas

  • 電子材料、光学材料、および磁性材料
  • 凝縮系物理学
  • コンピュータ サイエンスの応用
  • 応用数学
  • 電子工学および電気工学

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