Prof. Fei Gao from Singapore visited C-UFO
Author : Xin Chen

 Prof. Cheng-Wei Qiu from Nanyang technological university, Singapore, visited C-UFO on 26th December, 2017 and gave the public talk on " Topological electromagnetism and artificial surface electromagnetic wave ". Prof. Su Xu hosted the talk.


 By designing various electromagnetic structures (such as metamaterials and photonic crystals) to control the frequency of electromagnetic waves, wave loss and other degrees of freedom, the control of electromagnetic waves can be realized.Here I introduce two new modes of manipulation.The first is the use of a new dof - topology to control the electromagnetic wave, thereby giving rise to the topological electromagnetic field.Early studies of topological electromagnetism focused on how to design a two-dimensional topological electromagnetic structure and realize a topological waveguide with fault tolerance.In recent years, topological electromagnetic structure has been extended to 3d, but due to the difficulties in 3d structure processing, it is rarely realized in the optical band.As for the topological waveguide, two work are mainly introduced :(1) the design method of surface wave anomalous topological waveguide is proposed and experimentally verified; (2) the efficient compatibility method of topological waveguide and traditional waveguide is proposed and experimentally verified.The second kind of control mode is to use near field coupling to control electromagnetic wave on the surface.He describes how the forward/backward wave conversion and surface wave multipole mode interference can be achieved by using near field coupling.