Yu Ping, Li Jianxiong, Tang Chengchun, Cheng Hua, Liu Zhaocheng, Li Zhancheng, Liu Zhe, Gu Changzhi, Li Junjie, Chen Shuqi, Tian Jianguo
The MOE Key Laboratory of Weak Light Nonlinear Photonics, School of Physics, Teda Applied Physics Institute, and the 2011 Project Collaborative Innovation Center for Biological Therapy, Nankai University, Tianjin 300071, China.
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
Light Sci Appl. 2016 Jul 1;5(7):e16096. doi: 10.1038/lsa.2016.96. eCollection 2016 Jul.
Optical activity is the rotation of the plane of linearly polarized light along the propagation direction as the light travels through optically active materials. In existing methods, the strength of the optical activity is determined by the chirality of the materials, which is difficult to control quantitatively. Here we numerically and experimentally investigated an alternative approach to realize and control the optical activity with non-chiral plasmonic metasurfaces. Through judicious design of the structural units of the metasurfaces, the right and left circular polarization components of the linearly polarized light have different phase retardations after transmitting through the metasurfaces, leading to large optical activity. Moreover, the strength of the optical activity can be easily and accurately tuned by directly adjusting the phase difference. The proposed approach based on non-chiral plasmonic metasurfaces exhibits large optical activity with a high controllable degree of freedom, which may provide more possibilities for applications in photonics.
旋光性是指当线偏振光穿过旋光性材料时，其偏振面沿传播方向发生的旋转。在现有方法中，旋光性的强度由材料的手性决定，而手性难以进行定量控制。在此，我们通过数值模拟和实验研究了一种利用非手性等离子体超表面来实现和控制旋光性的替代方法。通过对超表面结构单元的合理设计，线偏振光的右旋和左旋圆偏振分量在穿过超表面后具有不同的相位延迟，从而导致较大的旋光性。此外，通过直接调节相位差，可以轻松且精确地调节旋光性的强度。所提出的基于非手性等离子体超表面的方法展现出具有高可控自由度的大旋光性，这可能为光子学应用提供更多可能性。
