Study On Near-field Optical Properties Of Quasicrystal And Related Metasurface

Surface plasmon polaritons play an important role in medical diagnosis,biochemical spectroscopy,communication and so on.Exciting and man ipulating surface plasmon polaritons have always been an important research direction in optics.In recent years,metal nanoslits array structures which can excite the surface plasmon polaritons causes a great deal of attention.In this dissertation,based on FDTD-method,meta-surface structures such as quasicrystal,periodic,and random distribution are designed and the properties are analyzed.The main research work in this dissertation is as follows:First,based on the traditional structure of surface plasmon polaritons,a periodic meta-surface structure is designed.This structure belongs to meta material,which can be used in manufacturing smaller optical devices and also be used to realize the ultratransmission of light.Illuminating the structure with proper wavelengths,we find that the field distribution of surface plasma polaritons excited by periodic meta-surface structure is more regular.When the polarization of the incident light changes,the field distribution of the surface plasmon polaritons excited by periodic meta-surface structure will change significantly.In addition,the transmission of the surface plasmon polaritons excited by periodic meta-surface structure will also change significantly when the incident wavelength is changed.Second,according to the principle of Penrose puzzle,the isotropic and anisotropic quasicrystal meta-surface structure with ten rotational symmetry are also designed by the Golden Section method.Compared with periodic meta-surface structure,quasicrystal meta-surface structure has higher rotational symmetry.When the surface plasmon polaritons excited by the quasicrystal meta-surface pass through the structure,the transmission directions exhibit interesting rotational symmetry.Quasicrystal meta-surface structure also shows the phenomenon of the ultratransmission of light.Its transmission also responds greatly to the changes in the wavelength of incident light.Finally,in addition to periodic meta-surface and quasicrystal meta-surface,a random meta-surface structure is also designed.The random meta-surface structure has a disordered distribution of slits.We find that the surface plasmon polaritons can also be excited by the random meta-surface.Its field distribution is in random.Moreover,the transmission of the random meta-surface structure also shows a great response to the wavelength of incident light.