Open AccessLossless dielectric metasurface with giant intrinsic chirality for terahertz wave
Author(s) -
Jie Li,
Jitao Li,
Chenglong Zheng,
Yang Yue,
Zhen Yue,
Xuanruo Hao,
Hongliang Zhao,
Fuyu Li,
Tingting Tang,
Liang Wu,
Jining Li,
Yating Zhang,
Jianquan Yao
Publication year - 2021
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.430033
Subject(s) - terahertz radiation , chirality (physics) , dipole , optics , circular polarization , electric dipole moment , physics , dielectric , magnetic dipole , metamaterial , optoelectronics , materials science , microstrip , chiral symmetry breaking , quantum mechanics , nambu–jona lasinio model , quark
It is difficult for single-layer metal metasurfaces to excite in-plane component of magnetic dipole moment, so achieving giant intrinsic optical chirality remains challenging. Fortunately, displacement current in dielectric metasurfaces can form the in-plane magnetic moment which is not orthogonal to the electric dipole moment and forms intrinsic chirality. Here, we show a lossless all-silicon metasurface which achieves giant intrinsic chirality in terahertz band. The leaky waveguide mode in the chiral silicon pillars simultaneously excite the in-plane electric and magnetic dipole moments, which triggers the spin-selected backward electromagnetic radiation, and then realizes the chiral response. The theoretical value of circular dichroism in the transmission spectrum reaches 69.4%, and the measured one is 43%. Based on the photoconductivity effect of the silicon metasurface, we demonstrate optical modulation of the intrinsic chirality using near-infrared continuous wave. In addition, by arranging the two kinds of meta-atoms which are enantiomers, we show the spin-dependent and tunable near-field image display. This simple-prepared all-silicon metasurface provides a new idea for the design of terahertz chiral meta-devices, and it is expected to be applied in the fields of terahertz polarization imaging or spectral detection.