Direct routing of intensity-editable multi-beams by dual geometric phase interference in metasurface

• Main Authors: Ding Guowen, Chen Ke, Luo Xinyao, Qian Guangxu, Zhao Junming, Jiang Tian, Feng Yijun
• Format: Article
• Language: English
• Published: De Gruyter 2020-06-01
• Series: Nanophotonics
• Subjects: circular polarization; geometric phase; metasurface; multifunctional
• Online Access: https://doi.org/10.1515/nanoph-2020-0203

Controlling spin electromagnetic waves by ultra-thin Pancharatnam-Berry (PB) metasurfaces show promising prospects in the optical and wireless communications. One of the major challenge is to precisely control over the complex wavefronts and spatial power intensity characteristics without relying on massive algorithm optimizations, which requires independent amplitude and phase tuning. However, traditional PB phase can only provide phase control. Here, by introducing the interference of dual geometric phases, we propose a metasurface that can provide arbitrary amplitude and phase manipulations on meta-atom level for spin waves, achieving direct routing of multi-beams with desired intensity distribution. As the experimental demonstration, we design two microwave metasurfaces for respectively controlling the far-field and near-field multi-beam generations with desired spatial scatterings and power allocations, achieving full control of both sophisticated wavefronts and their energy distribution. This approach to directly generate editable spatial beam intensity with tailored wavefront may pave a way to design advanced meta-devices that can be potentially used in many real-world applications, such as multifunctional, multiple-input multiple-output and high-quality imaging devices.