Study On The All-Metal And Metal-Dielectric Multilayer Metamaterial Absorber

With the rapid development of micro-nano fabrication technology,micro-nano devices are becoming more miniaturized and integrated,and devices based on the interaction between light and matter are further studied.Surface plasmon polaritons(SPPs),which are evanescent waves propagating along metal surfaces,can be excited by the interaction between photons and matter.SPPs have attracted wide attention in the fields of light absorption,optical transmission enhancement,antenna and so on.Absorber is an important application field of surface plasmon.Absorber can be divided into two kinds according to the actual application.One is narrowband absorber,which is an important application of giant in sensor.There is also a broadband absorber,in energy absorption,stealth and other aspects have been a great application.According to the materials used by the absorber,it can also be divided into all-medium,all-metal,multi-layer metal-medium absorber.In this thesis,two kinds of metamaterial structures are constructed based on metal surface plasmon resonance,and the finite difference time domain method is used to construct the model and carry out numerical simulation,optimization and relevant mechanism exploration.The multilayer metal-dielectric material absorber and the all-metal material absorber are realized.1.The research background of metamaterials and the research status of perfect absorbers based on surface plasmon metamaterials are introduced.2.The theoretical basis of metamaterial absorber is introduced,including the development of surface plasmons,principle,impedance matching theory,equivalent medium theory,electromagnetic simulation software based on FDTD.3.A five-layer ultra-wideband perfect absorber for nanomaterials and its preparation method are proposed to achieve near-perfect absorption of wavelengths ranging from 785 nm to 2675 nm.It can be prepared over a large area at a low cost by micro-nano preparation technology.In addition,when the incident Angle of light increases from 0° to 40°,the UWB absorptivity still maintains good absorption efficiency.These advantages make the UWB a near-perfect light absorber.There is huge potential in areas such as solar thermal energy harvesting,thermoelectric components and imaging4.An ultra-wide band absorber based on all-metal materials is proposed.Due to the mutual coupling of air cavity and metallic surface plasmons,the absorber can achieve a perfect absorption of over 90% wavelength from 493 nm to 3590 nm.We also discuss the effects of different parameters,incident light Angle,polarization Angle and metal materials on its absorption performance.The structure has a broad application prospect in the fields of solar energy absorption,photoelectric detection and electromagnetic stealth.The above design structure has the characteristics of perfect absorption,high temperature resistance,large Angle incident is not sensitive,and so on.The distribution of electric field and magnetic field of the absorber structure is calculated by numerical simulation software to further explore the principle of realizing broadband absorption of the absorber.Through the design of the absorber structure,the explanation of the theory,and combined with the actual environment conditions,we proposed two kinds of absorber has a certain feasibility,has the potential application value.