Spin-Selective Transmission in Chiral Folded Metasurfaces.
Spin-Selective Transmission in Chiral Folded Metasurfaces.
复制标题
DOI：
10.1021/acs.nanolett.8b04521
复制
发表时间：
2019-01
期刊：
影响因子：
10.8
通讯作者：
Shengyan Yang;Zhe Liu;Sha Hu;A. Jin;Haifang Yang;Shuang Zhang;Junjie Li;C. Gu
中科院分区：
文献类型：
--
作者：
Shengyan Yang;Zhe Liu;Sha Hu;A. Jin;Haifang Yang;Shuang Zhang;Junjie Li;C. Gu
控制光的自旋角动量（或圆偏振态）在光通信、圆二色光谱和量子信息处理等现代光子应用中起着至关重要的作用。然而，传统的方法来操纵光的自旋需要天然存在的手性或双折射材料，由于弱的光-物质相互作用而体积庞大。在这里，我们通过实验证明了一种在红外区域实现自旋选择性传输的方法，该方法基于手性折叠超表面，能够传输光的一种自旋状态，而在很大程度上禁止另一种自旋状态。由于折叠后的超表面具有固有的手性，实验证明其圆二色性可达0.7，最大透过率超过92%。这种巨大的圆二色性是在电荷-电流多极膨胀的框架下解释的。此外，通过控制超表面相对于基本平面的折叠角，可以很容易地控制本征手性。由于其强大的手性和自旋依赖的传输特性，所提出的折叠超表面可以应用于光通信技术和生物光子学的一系列新型光子自旋选择器件。
Controlling the spin angular momentum of light (or circular polarization state) plays a crucial role in the modern photonic applications such as optical communication, circular dichroism spectroscopy, and quantum information processing. However, the conventional approaches to manipulate the spin of light require naturally occurring chiral or birefringent materials of bulky sizes due to the weak light-matter interactions. Here we experimentally demonstrate an approach to implement spin-selective transmission in the infrared region based on chiral folded metasurfaces that are capable of transmitting one spin state of light while largely prohibiting the other. Due to the intrinsic chirality of the folded metasurface, a remarkable circular dichroism as large as 0.7 with the maximum transmittance exceeding 92% is experimentally demonstrated. The giant circular dichroism is interpreted within the framework of charge-current multipole expansion. Moreover, the intrinsic chirality can be readily controlled by manipulating the folding angle of the metasurface with respect to the cardinal plane. Benefiting from its strong chirality and spin-dependent transmission characteristics, the proposed folded metasurface may be applied to a range of novel photon-spin selective devices for optical communication technologies and biophotonics.