Liu Yongjian, Zhang Taiming, Cai Jixiang, Zhang Fei, He Qiong, Pu Mingbo, Guo Yinghui, Bao Hanlin, Ma Xiaoliang, Li Xiong, Luo Xiangang
National Key Laboratory of Optical Field Manipulation Science and Technology, Chinese Academy of Sciences, Chengdu 610209, China.
State Key Laboratory of Optical Technologies on Nano-Fabrication and Micro-Engineering, Institute of Optics and Electronics, Chinese Academy of Sciences, Chengdu 610209, China.
ACS Appl Mater Interfaces. 2024 Jul 3;16(26):33935-33942. doi: 10.1021/acsami.4c03439. Epub 2024 Jun 20.
Simultaneous circular dichroism and wavefront manipulation have gained considerable attention in various applications, such as chiroptical spectroscopy, chiral imaging, sorting and detection of enantiomers, and quantum optics, which can improve the miniaturization and integration of the optical system. Typically, structures with n-fold rotational symmetry ( ≥ 3) are used to improve circular dichroism, as they induce stronger interactions between the electric and magnetic fields. However, manipulating the wavefront with these structures remains challenging because they are commonly considered isotropic and lack a geometric phase response in linear optics. Here, we propose and experimentally demonstrate an approach to achieve simultaneous circular dichroism (with a maximum value of ∼0.62) and wavefront manipulation using a plasmonic metasurface made up of C3 Archimedes spiral nanostructures. The circular dichroism arises from the magnetic dipole-dipole resonance and strong interactions between adjacent meta-atoms. As a proof of concept, two metadevices are fabricated and characterized in the near-infrared regime. This configuration possesses the potential for future applications in photodetection, chiroptical spectroscopy, and the customization of linear and nonlinear optical responses.
同时进行圆二色性和波前操控在诸如手性光谱学、手性成像、对映体的分选与检测以及量子光学等各种应用中受到了广泛关注，这能够提升光学系统的小型化和集成度。通常，具有n重旋转对称性（n≥3）的结构被用于增强圆二色性，因为它们能在电场和磁场之间引发更强的相互作用。然而，利用这些结构来操控波前仍然具有挑战性，因为它们通常被认为是各向同性的，并且在线性光学中缺乏几何相位响应。在此，我们提出并通过实验证明了一种利用由C3阿基米德螺旋纳米结构组成的等离激元超表面来实现同时圆二色性（最大值约为0.62）和波前操控的方法。圆二色性源于磁偶极 - 偶极共振以及相邻超原子之间的强相互作用。作为概念验证，制作了两个超表面器件并在近红外波段进行了表征。这种配置在光探测、手性光谱学以及线性和非线性光学响应定制方面具有未来应用潜力。
