Wavefront Manipulation And Beam Forming By Metasurface

The appearance of the metasurface makes the manipulation of electromagnetic beam step into a new stage.The devices based on the metasurface can realize planar photonics.Because of their small size and light weight,they can be integrated into nano-photonic chips.This technology has a broad development prospect in the fields of sensor,microscopy,ultrafast information technology,optoelectronics and so on.In this thesis,the application of the metasurface in wave front manipulation and beam forming is studied.In this thesis,the research progress of metasurface at home and abroad is reviewed,and then the main theories used in this thesis are introduced,such as generalized Snell’s law,the polarization state of light and its transmission theory,geometric phase and transmission phase theory,etc.Then,start from the simple focusing principle of lens,combining the geometric phase principle and Fresnel-Kirchhoff diffraction theory,the phase configuration required to realize the imaging of arbitrary curves that have subwavelength resolution on the focusing plane is derived,and a new qualitative method of polarization state detection and a new method of angle detection of incident polarized light are proposed.Finally,the scattering characteristics of dielectric cell structures based on silicon nanocrystalline materials are studied,and a parameter library is established for the one-to-one correspondence between the transmittance together with the phase of the same polarization and the length and width of the nanocrystalline materials,and the beam deflector and vortex beam generator that work in infrared band with transmission efficiency over 75% are designed and simulated based on the co-polarization transmission phase.The imaging method proposed in this thesis based on the implementation of the mtasurface has sub-wavelength resolution,and the polarization detection method is intuitive and easy to operate,which provides a new idea for the metasurface imaging.The beam deflector and vortex beam generator designed by simulation have high transmission efficiency,compact structure and easy integration,which has some guiding significance for engineering practice.