All-dielectric chiral coding metasurface based on spin-decoupling in terahertz band

Nanophotonics

article

Chenglong Zheng¹  Yating Zhang¹  Yan Zhang²  Jianquan Yao¹  Jie Li¹  Guocui Wang³  Jitao Li¹  Silei Wang¹  Mengyao Li¹  Hongliang Zhao¹  Zhen Yue¹ 

[1] Key Laboratory of Opto-Electronics Information Technology (Tianjin University), Ministry of Education, School of Precision Instruments and Opto-Electronics Engineering, Tianjin University;Beijing Key Laboratory for Metamaterials and Devices, Key Laboratory of Terahertz Optoelectronics, Ministry of Education, Beijing Advanced Innovation Center for Imaging Technology, Department of Physics, Capital Normal University;Beijing Engineering Research Center for Mixed Reality and Advanced Display, School of Optics and Photonics, Beijing Institute of Technology

关键词: all-dielectric metasurface;    circular dichroism;    decoupling;    terahertz;   

DOI  :  10.1515/nanoph-2020-0622

学科分类：社会科学、人文和艺术（综合）

来源: De Gruyter

【 摘 要 】

Metamaterials can achieve superior electromagnetic properties over natural materials by adjusting the structure of the meta-atoms. Chiral metamaterials have been widely used in circular dichroism (CD) spectra, polarization imaging, and optical sensing. Here we propose a kind of all-silicon coding metasurfaces to achieve the function similar to chirality by spin decoupling. One of the two circularly polarized (CP) channels is scattered randomly, and the desired function is only designed in the other opposite CP channel. Three kinds of coding metasurfaces are designed to verify the reliability of such approach: one simultaneously possessing dual function of transmitting directly and scattering randomly, one capable of generating the superposition state of vortex beam, and the other generating the Bessel vortex beam, respectively. And some experimental verifications are carried out. This scheme is simpler and more versatile than previous schemes which require elaborate designed structure of the meta-atoms. Our novel approach provides a new option for implementing tunable chirality.

【 授权许可】

CC BY