Abstract

Chirality has received wide attention due to its promising applications in biopharmaceuticals, chemical detection, and polarized optoelectronic devices. Herein, metamaterials with layered Tai Chi patterns are proposed to get strong and tunable chirality. Based on the surface current distribution analysis, a coupling model considering both the magnetic and electric dipoles in the upper and bottom metallic structures is proposed to understand the circular dichroism. Accordingly, both an external chiral modulation by changing the incident angle and an internal chiral modulation by changing the twist angle are achieved. Incident-angle-dependent circular dichroism modulation exhibits a range of 0.44–0.62 and the twist-angle-dependent modulation range is ${-}{0.6 - 0.42}$, where the negative value means the polarity of the circular dichroism can also be tuned. This work deepens the understanding of angular-dependent chirality in metamaterials and expands the potential for terahertz polarization optoelectronic applications.

© 2020 Optical Society of America

Angle enhanced circular dichroism in bilayer 90°-twisted metamaterial

Pengtao Lai, Guohua Dong, Wei Wang, Tao Chen, Tingting Lv, Bo Lv, Zheng Zhu, Yuxiang Li, Chunying Guan, and Jinhui Shi
Opt. Express 28(10) 15071-15080 (2020)

Reconfigurable metamaterial for chirality switching and selective intensity modulation

Shihao Li, Kejian Chen, Dajun Zhang, Yan Chen, Yeli Xu, Ji Liu, Xiong Wang, and Songlin Zhuang
Opt. Express 28(23) 34804-34811 (2020)

Chiral biosensing using terahertz twisted chiral metamaterial

Min Zhang, Danni Hao, Shuai Wang, Rui Li, Shou Wang, Yanqing Ma, Ramiro Moro, and Lei Ma
Opt. Express 30(9) 14651-14660 (2022)

Coexistence of circular dichroism and asymmetric transmission in a stretchable chiral metamaterial

Lei Zhou, Yuanhong Peng, Yueke Wang, Mengjia Lu, Jiaxin Zhou, Jian Ding, and Tian Sang
J. Opt. Soc. Am. B 37(12) 3763-3768 (2020)

Strongly tunable circular dichroism in gammadion chiral phase-change metamaterials

Tun Cao, Lei Zhang, Robert E. Simpson, Chenwei Wei, and Martin J. Cryan
Opt. Express 21(23) 27841-27851 (2013)