Abstract
The metasurface has emerged in the last decade as a highly desirable tool for manipulating electromagnetic (EM) waves. The Huygens’ metasurface provides a response to electric and magnetic fields, and as thus allows one to perfectly satisfy Maxwell’s boundary equations, and thereby achieve highly efficient, wide-angle and broadband wave transformations, without any spurious components whatsoever. Whilst most metasurfaces are constructed from discrete unit cells, most contemporary works on metasurfaces try to avoid the discretization effects by achieving very fine discretization. In this talk, I shall advocate the merits of coarse-discretization: I shall explain why there both obvious and surprising benefits to using fewer metasurface elements over the same spatial area. I will present my recent research in passive and active metasurfaces to illustrate this conjecture. They include: a bipartite Huygens’ metasurface that achieves perfect anomalous reflection, and a Huygens’ box that supports arbitrary electromagnetic waveform generation inside an enclosed volume, along the way, I shall also discuss the antenna and super-resolution imaging applications that either inspired these works or represent areas of potentially impactful applications.
Biosketch
Alex M. H. Wong is an Assistant Professor in applied electromagnetics, in the Department of Electronic Engineering at the City University of Hong Kong. He is also a member of the State Key Laboratory of Terahertz and Millimeter Waves. He obtained his doctoral degree (Ph.D. 2014) in Electrical Engineering, then served briefly as a postdoctoral fellow at the University of Toronto in Toronto, Canada. He has advanced multiple projects on superoscillation-based imaging, “smart train” radar, and next-generation RF, infrared and optical metasurfaces. Alex’s current research lies broadly in the areas of metasurfaces, metamaterials and super-resolution systems. He has received several accolades which include an IEEE RWP King Award (for the best annual publication by a young author in the IEEE Transactions on Antennas and Propagation), an URSI Young Scientist Award, a Raj Mittra Grant, IEEE doctoral research awards from the AP and MTT societies and the national NSERC Canada Graduate Scholarship. He is a member of the IEEE (AP and MTT Societies).