| Plasma metamaterial is a man-made material,meeting the requirements of microminiaturization and integration,which has become one of the research hotspots of nanophotonics in recent years,and it is widely used in aircraft cloaking,light-to-heat conversion,biochemical detection,electromagnetic imaging,RF,antennas and so on.Thesis aims to design high-performance plasma components,and the main works are listed as following:(1)A broadband absorber based on nanodisks array is designed.Due to the combination of the excitation of localized surface plasmon resonance,the propagating surface plasmon resonance,and the FP cavity of the structure,the absorber realizes impedance matching between the structure and the free space.The average absorption of the structure exceeds 98.4% in the visible and mid-infrared range,and the structure is not sensitive to polarization and has the characteristics of wide-angle absorption.Simulation results show that the nanostructure has possibilities in the fields of thermal imaging and photovoltaic cells.(2)We proposes a broadband absorber based on 2D metamaterials.The absorber consisting of metal-dielectric-metal and multiple metal-dielectric layers has an average absorption of 97.5% and an operating bandwidth of 4.6 μm within the wavelength range of 0.4-5 μm.The impedance calculation results prove that the structure is more suitable to realizing impedance matching between the structure and free space in the operating wavelength range.In addition,the effects of structural parameters,the number of metaldielectric layers,and oblique incidence on absorption characteristics are also studied.(3)An ultra-wideband absorber composed of multilayered metal-dielectric films is designed.This lithography-free structure is not only easy to manufacture,cheap,and stable,but also exhibits excellent broadband absorption characteristics.Besides,for different working frequency bands,the optimal geometric dimensions are given here. |
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