Direction-Controlled Bifunctional Metasurface Polarizers
Direction-Controlled Bifunctional Metasurface Polarizers
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DOI：
10.1002/lpor.201800198
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发表时间：
2018-12-01
影响因子：
11
通讯作者：
Yang, Xiaodong
中科院分区：
文献类型：
--
作者：
Chen, Yang;Gao, Jie;Yang, Xiaodong
由面内亚波长纳米结构组成的亚表面在控制光的振幅、位相和偏振态方面具有前所未有的能力。提出了一种基于等离子体阶梯槽二聚体的定向控制双功能亚表面偏振器，并对其进行了实验验证。在正向，启用手性线性偏振器，其仅允许传输特定的入射利手，并将其转换为指定的线偏振。在后向，亚表面起各向异性圆偏振器的作用，以选择性地将特定的线偏振分量转换为所需的圆偏振传输。观察到的方向受控的偏振选择和转换可以用双层结构内部的自旋相关模式耦合过程来解释。进一步展示了基于所提出的准表面偏振器的各向异性手性成像。这些结果为实现未来用于结构光转换、矢量光束产生、光学成像和传感以及光通信的多功能光子集成器件提供了新的自由度。
Metasurfaces composed of in-plane subwavelength nanostructures have unprecedented capability in manipulating the amplitude, phase, and polarization states of light. Here, a unique type of direction-controlled bifunctional metasurface polarizer is proposed and experimentally demonstrated based on plasmonic stepped slit-groove dimers. In the forward direction, a chiral linear polarizer is enabled which only allows the transmission of a certain incident handedness and converts it into the specified linear polarization. In the backward direction, the metasurface functions as an anisotropic circular polarizer to selectively convert a certain linear polarization component into the desired circularly polarized transmission. The observed direction-controlled polarization selection and conversion are explained by the spin-dependent mode coupling process inside the bilayer structure. Anisotropic chiral imaging based on the proposed metasurface polarizer is further demonstrated. The results provide new degrees of freedom to realize future multifunctional photonic integrated devices for structured light conversion, vector beam generation, optical imaging and sensing, and optical communication.