Polarization Independent Achromatic Meta-Lens Designed for the Terahertz Domain

Frontiers in Physics

Jianqiang Gu¹  Jiaguang Han¹  Yufei Gao¹  Ridong Jia¹  Zhen Tian¹  Chunmei Ouyang¹  Weili Zhang² 

[1] Tianjin, China;Tianjin, China;Stillwater, OK, United States;

关键词: achromatic;    meta-lens;    polarization independent;    terahertz;    metasurfaces;   

DOI  :  10.3389/fphy.2020.606693

来源: Frontiers

【 摘 要 】

In recent years, metasurface-based focusing elements have gradually become an indispensable type of terahertz lenses. However, the meta-lens often suffers from chromatic aberration due to the intrinsic dispersion of each element, especially in the broadband application scenarios. In this paper, we design and demonstrate a silicon-based achromatic meta-lens working from 0.6 to 1.0 THz, which is polarization insensitive because of the adopted symmetrical structures. The simulated focal length and the full width at half maximum (FWHM) of the foci at different frequencies prove the achromatic behavior of our meta-lens compared with the chromatic counterpart. We also show that the focus shift incongruence of our design originates from the transmission amplitude distribution of the meta-lens. This article not only provides an achromatic planar lens working at terahertz domain but also reveals the importance of the amplitude distribution in the achromatic metasurface design.

【 授权许可】

CC BY