Polarization-independent all-silicon dielectric metasurfaces in the terahertz regime

• Published in: 光子学研究：英文版 2018, Vol.9 (1), p.24-29
• Main Authors: HUIFANG ZHANG, XUEQIAN ZHANG, QUAN Xu, QIU WANG, YUEHONG Xu, MINGGUI WEI, YANFENG LI, JIANQIANG GU, ZHEN TIAN, CHUNMEI OUYANG, XIXIANG ZHANG, CONG Hu, JIAGUANG HAN, AND WEILI ZHANG
• Format: Article
• Language: English
• Subjects: 光学; 红外范围; 通讯技术; 半导体
• ISSN: 2327-9125; 2327-9125

Dielectric metasurfaces have achieved great success in realizing high-efficiency wavefront control in the optical and infrared ranges. Here, we experimentally demonstrate several efficient, polarization-independent, all-silicon dielectric metasurfaces in the terahertz regime. The metasurfaces are composed of cylindrical silicon pillars on a silicon substrate, which can be easily fabricated using etching technology for semiconductors. By locally tailoring the diameter of the pillars, full control over abrupt phase changes can be achieved. To show the controlling ability of the metasurfaces, an anomalous deflector, three Bessel beam generators, and three vortex beam generators are fabricated and characterized. We also show that the proposed metasurfaces can be easily combined to form composite devices with extended functionalities. The proposed controlling method has promising applications in developing low-loss, ultra-compact spatial terahertz modulation devices.