Researches On The Plasmonics Polarization-devices Based On Metasurfaces Microstructures

The rapid developments of planar and ultrathin metasurfaces have exhibited unprecedented abilities for manipulating beams, which will lead to a new class of high-performance ultrathin and flat optical components in the areas of integrated optics, flat displays, superresolution imaging, data storage, quantum information processing and so forth. Therefore, it is significant to investigate the characteristics and practical applications of metasurfaces. In this dissertation, base on the PB phase theory and the FDTD simulation method, we have investigated the characteristics of the metasurface for the circularly polarized light. The researching contents can be concluded as follows:(1) Propose a novel plasmonics metasurface, which is composed of the metal rectangular split-ring resonators (MRSRR) array. According to the basic principle of PB phase, a circular polarization analyzer based on the metasurface is designed, which can realize the separation of circularly polarized light and the decomposition of linearly polarized light. The desired PB phase can be achieved conveniently and efficiently by modulating the optical-axis of the MRSRR.(2) The method of improving the polarization conversion efficiency with the novel metasurface has been proposed and investigated. With the help of the numerical simulation, the metasurface composed of nano-aperture in gold film is proposed for both linearly polarized and circularly polarized light, which exhibits high polarization conversion efficiency. Meanwhile, the metasurface can also be used for a circularly polarized half wave plate, as well as a quarter wave plate to achieve linear polarized light conversion to the circularly polarized.(3) A novel metalens designing method is proposed for the arbitrary focusing. This theme combines the CGH method with the characteristics of metasurface, which improves the ability of designing meatlens. Furthermore, a variety of metalenses are designed and investigated by simulation, such as on-and off-axis focusing and multiple spots focusing for circularly polarized incident lights, which exhibits excellent focusing ability.(4) A broadband and high-efficiency polarization conversion metalens based on dielectric meta-reflectarray has been proposed. We design and verify metalenses for on-axis focusing, off-axis focusing and four point focusing and the relationship between the focal length of the lens and the incident wavelength is investigated by means of simulation.