He Xiaoyuan, Deng Li, Yang Yang, Feng Botao
Opt Express. 2021 Apr 12;29(8):12736-12749. doi: 10.1364/OE.422664.
Metasurface offers a promising platform in the design of multifunctional devices owing to its unique ability for EMWs manipulation. However, wave-manipulation capabilities for metasurfaces face challenges in manipulating orthogonal EMWs with arbitrary circularly or elliptically polarized EMWs in the microwave region. Herein, single-layer reflective metasurfaces are proposed for independent manipulation of an arbitrary set of orthogonal circularly or elliptically polarized EMWs via polarization-decoupled phase. Taking advantage of single-layer anisotropic meta-atoms, the proposed metasurface can act as a tandem phase modulator, which introduces polarization-decoupled phase profiles for arbitrary circularly and elliptically polarized EMWs based on the Jones matrix. In this way, the proposed metasurface can distinguish a set of orthogonal EMWs with circular or elliptical polarization states and impose arbitrary phase profiles on them independently and simultaneously. For proof-of-concept, bifunctional metasurfaces operating in the microwave region are presented for independent manipulation of three different sets of orthogonal circularly or elliptically polarized EMWs. They create dual independent channels associated with a pair of orthogonal polarization states, performing functions including polarization beam splitting and orbital angular momentum (OAM) multiplexing. Measured and simulated results show a good agreement, confirming that the proposed single-layer reflective metasurfaces are efficient devices that enable meta-devices to independently control arbitrary circular and elliptical polarized EMWs, achieving arbitrary functionalities.
超表面由于其对电磁波的独特操控能力,为多功能器件的设计提供了一个很有前景的平台。然而,超表面的波操控能力在微波区域中对具有任意圆极化或椭圆极化的正交电磁波进行操控时面临挑战。在此,提出了一种单层反射超表面,用于通过极化解耦相位独立操控任意一组正交圆极化或椭圆极化的电磁波。利用单层各向异性的元原子,所提出的超表面可以作为一个串联相位调制器,基于琼斯矩阵为任意圆极化和椭圆极化的电磁波引入极化解耦相位分布。通过这种方式,所提出的超表面能够区分一组具有圆极化或椭圆极化状态的正交电磁波,并同时独立地在它们上面施加任意的相位分布。为了验证概念,展示了在微波区域工作的双功能超表面,用于独立操控三组不同的正交圆极化或椭圆极化的电磁波。它们创建了与一对正交极化状态相关的两个独立通道,执行包括极化光束分裂和轨道角动量(OAM)复用等功能。测量结果与模拟结果吻合良好,证实了所提出的单层反射超表面是能够使超器件独立控制任意圆极化和椭圆极化电磁波、实现任意功能的高效器件。