报告题目 | Metasurfaces: Physics and Applications |
报告人 | 周磊 教授 |
报告人单位 | 复旦大学 |
报告时间 | 2020-11-20 (周五) 10:00 |
报告地点 | 上海研究院4号楼329报告厅(物质楼B1102同步视频) |
主办单位 | 中国科学院量子信息与量子科技创新研究院 |
报告介绍 | 报告摘要:The arbitrary control of electromagnetic (EM) waves is a key aim of photonic research. Conventional optical materials have limited abilities to manipulate EM waves due to their narrow variation ranges of material parameters. Metamaterials, artificial materials constructed by subwavelength-sized microstructures (e.g., meta-atoms) exhibiting tailored EM properties, can in principle possess arbitrary values of electric permittivity and magnetic permeability, and thus exhibit unprecedented capabilities to control EM waves. However, the inevitable wave-transportation losses in such complex media hinder their practical applications. Very recently, metasurfaces, the two-dimensional version of metamaterials composed by planar meta-atoms arranged in specific macroscopic orders, have attracted extensive attention, as they can not only largely avoid the losses but also exhibit even stronger capabilities to control EM waves. Many fascinating wave-control phenomena were discovered based on metasurfaces, such as anomalous refraction/reflection based on the generalized Snell’s law, planar-lens focusing and optical vortex generalizations. In this Colloquium, I will present a brief overview on the historical development of this fast-developing research field, focusing particularly on our recent efforts in employing meta-surfaces to control EM waves in various aspects. Specifically, I will describe how to realize utilize gradient metasurfaces to convert propagating waves surface waves with nearly 100% efficiency and how to realize photonic spin-Hall effects with carefully designed meta-surfaces with nearly 100% efficiency in both reflection and transmission geometries. Finally, I will introduce our latest efforts on developing a theoretical framework from first principles (e.g., Maxwell equations) to study coupled photonic systems and control the angular dispersions in metasurfaces. |