Circular Polarized Wave Manipulation And Smith-purcell Radiation Based On Chiral Metamaterials

Metamaterials are artificial structures arranged periodically and engineered at the subwavelength scale.Owing to their unique electrical,magnetic,optical properties,metamaterials have attracted extensive interest over the past years due to their great capabilities in manipulating the propagation of electromagnetic wave.Metasurfaces are two-dimension versions of metamaterials,which are easy to realize by plane technology.The controlling of high energy particle radiation has been widely used in areas such as molecular imaging,electron laser source and particle detection.The study of controlling high energy particle radiation using metamaterials is a cutting-edge in the cross research areas of high energy physics,material science and electromagnetic science,which has great significance for the integrated development of related disciplines.In this thesis,we focus on the issue of manipulation designated circularly polarized waves and high energy particle radiation which are difficult to be directly experimentally verified.We systematically investigate the manipulation circular dichroism,asymmetric transmission,reconfigurable ability and Smith-Purcell radiation,which provides important technical support for the practical application of new metamaterials and devices in this field.The contents of thesis can be catalogued as follows:1.Based on symmetry analysis of Jones matrix and Pancharatnam-Berry phase principle,a general method is proposed and experimentally demonstrated to design a gradient chiral metamirror for spin-selective anomalous reflection.Moreover,based on the chiral unit cell which transmits a designated circularly polarized wave while totally reflects the another one,and PB-phase principle,we propose and experimentally demonstrate a general method to design full space controlling asymmetric transmission devices.2.Based on deformation technology,we propose and experimentally demonstrate a general method to design reconfigurable metamaterials.We design an origami-based reconfigurable metamaterial,whose electromagnetic response can be switched between nonchiral and chiral states at dual-band frequencies.Futhermore,single-band,dual-band and broadband chiral metamaterials with reconfigurable performance are designed and experimentally demonstrated based on kirigami deformation technology.3.A general method to complete control of Smith-Purcell radiation based on metasurfaces is proposed.We design a bianisotropic metasurface to control the polarization state of the Smith-Purcell radiation.Moveover,gradient chiral metasurfaces are proposed which can manipulate the propagation direction of the Smith-Purcell radiation.Futhermore,we propose and experimentally demonstrate a new method to generate vortex Smith-Purcell radiation which can control the orbit angular momentum.