Yang Shijun, Li Yanfeng, Chen Xieyu, Yang Quanlong, Han Jiaguang, Zhang Weili
Opt Lett. 2020 Nov 15;45(22):6146-6149. doi: 10.1364/OL.403377.
Chiral metamaterials have attracted wide interest because strong optical activity at designed frequencies could be achieved beyond that in natural materials. Here we propose an all-dielectric metamaterial with strong extrinsic circular dichroism and circular birefringence by periodically arranging symmetry-broken dielectric Mie resonators at terahertz frequencies. The strong interaction between the electric and magnetic resonances from circularly polarized incident waves dominates the performance of the all-dielectric metamaterial, which exhibits a 60% circular dichroism in transmission and a polarization rotation angle of 60° at maximum, respectively. Additionally, the spectral range of the circular dichroism with preserved amplitude can be adjusted continuously in the frequency range from 0.67-0.79 THz by tuning the tilt angle of the incident wave. Our findings will be of great potential in polarization control applications such as asymmetric transmission, optical isolation, and on-chip chiral manipulation.
手性超材料引起了广泛关注，因为在设计频率下可以实现比天然材料更强的光学活性。在此，我们提出一种全介质超材料，通过在太赫兹频率下周期性排列对称性破缺的介质米氏谐振器，实现强外在圆二色性和圆双折射。圆偏振入射波产生的电共振和磁共振之间的强相互作用主导了全介质超材料的性能，该超材料在传输中表现出60%的圆二色性，最大偏振旋转角为60°。此外，通过调整入射波的倾斜角度，在0.67 - 0.79太赫兹的频率范围内，可以连续调节具有保留幅度的圆二色性的光谱范围。我们的研究结果在诸如非对称传输、光隔离和片上手性操纵等偏振控制应用中具有巨大潜力。
