All-dielectric metalens for terahertz wave imaging.
Xue Jiang,Hao Chen,Zeyu Li,Hong-Kuan Yuan,Luyao Cao,Luo Zhenfei,Kun Zhang,Zhihai Zhang,Zhongquan Wen,Li-Guo Zhu,Xun Zhou,Gaofeng Liang,Desheng Ruan,Du Lianghui,Lingfang Wang,Gang Chen +15 more
TLDR
This work proposes a metalens based on an all-dielectric metasurface with a sub-wavelength unit size of 0.39λ for terahertz wave imaging and experimentally demonstrate its performance in focusing and imaging, and demonstrates the reversibility of the metalens for imaging.Abstract:
Terahertz wave imaging offers promising properties for non-destructive testing applications in the areas of homeland security, medicine, and industrial inspection. However, conventional optical lenses are heavy and bulky and difficult to integrate. An all-dielectric metasurface provides an attractive way to realize a planar lens of light weight that is ultrathin and offers ease of integration. Terahertz lenses based on various metasurfaces have been studied, especially for the application of wave focusing, while there are few experimental demonstrations of terahertz wave imaging lenses based on an all-dielectric metasurface. In the present work, we propose a metalens based on an all-dielectric metasurface with a sub-wavelength unit size of 0.39λ for terahertz wave imaging and experimentally demonstrate its performance in focusing and imaging. A large numerical aperture metalens was fabricated with a focal length of 300λ, radius of 300λ, and numerical aperture of 0.707. The experimental results show that the lens can focus THz waves with an incident angle up to 48°. More importantly, clear terahertz wave images of different objects were obtained for both different cases of forward- and inverse-incident directions, which demonstrate the reversibility of the metalens for imaging. Such a metalens provides a way for realization of all-planar-lens THz imaging system, and might find application in terahertz wave imaging, information processing, microscopy, and others.read more
Citations
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Journal ArticleDOI
Dielectrics for Terahertz Metasurfaces: Material Selection and Fabrication Techniques
TL;DR: In this article, an overview of dielectric materials employed as spacers, and fabrication methods employed to realize these devices at the terahertz frequency range are also presented; material selection guidelines, material-specific and application-specific fabrication quality metrics are outlined, and new techniques are proposed.
Journal ArticleDOI
Broadband achromatic metalens in terahertz regime
Qingqing Cheng,Ma Meilin,Dong Yu,Zhixiong Shen,Jingya Xie,Juncheng Wang,Nianxi Xu,Hanming Guo,Wei Hu,Shuming Wang,Tao Li,Songlin Zhuang +11 more
TL;DR: In this paper, the authors proposed an achromatic metalens with C-shaped unit elements working from 0.3 to 0.8 GHz with a bandwidth of approximately 91% over the center frequency.
Journal ArticleDOI
Metallic and dielectric metasurfaces in photoconductive terahertz devices: A review
A. E. Yachmenev,D. V. Lavrukhin,I. A. Glinskiy,Nikolay V. Zenchenko,Yurii G. Goncharov,Igor E. Spektor,Rustam A. Khabibullin,Rustam A. Khabibullin,Taiichi Otsuji,Dmitry Ponomarev +9 more
TL;DR: In this paper, the authors highlight recent and novel trends focused on metallic (plasmonic) and dielectric metasurfaces in photoconductive terahertz (THz) devices.
Journal ArticleDOI
A high numerical aperture, polarization-insensitive metalens for long-wavelength infrared imaging
TL;DR: In this paper, a polarization-insensitive, all-dielectric flat metalens operating at the long-wavelength infrared (LWIR) has been demonstrated, which can focus incident light down to a spot as small as ∼1.08λ and exhibits high-resolution imaging performance.
Journal ArticleDOI
Metasurfaces for manipulating terahertz waves
Xiaofei Zang,Bingshuang Yao,Lin Chen,Jingya Xie,Xuguang Guo,Alexei V. Balakin,Alexander P. Shkurinov,Songlin Zhuang +7 more
TL;DR: In this paper, the authors focus on recent advancements in metamaterials for the wavefront manipulation of terrahertz (THz) waves, including the planar metalens, holograms, arbitrary polarisation control, special beam generation, and active metasurface devices.
References
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