Research On All-Metal Metamaterial Absorber And Its Absorption And Sensing Characteristics

Metamaterial is a composite material composed of periodic arrangements of unit structures of a specific shape.Because of its novel characteristics not found in natural materials,it is widely used in electromagnetic stealth,lenses,artificial black holes,etc.Among them,metamaterial absorbers are also an important application.With the deepening of research,metamaterial absorbers are mainly divided into two types according to the needs in practical applications.One is a wide-band absorber,which is mainly used in stealth,solar cells,and solar light-toheat conversion.The other is a narrow-band absorber,which has been widely used in sensing and detection.In this paper,two types of absorbers are designed using metal materials,and the corresponding absorption,and refractive index-sensing performances are studied.1.An ultra-wideband metamaterial absorber based on an all-metal connected cylindrical cavity structure is designed.The absorbance of the absorber in the wavelength range of 300nm?1260nm(ie.,ultraviolet,visible light,and infrared)exceeds 90%,and two resonance peaks appear in this absorption wavelength range.The first resonance peak is at 389 nm,the second resonance peak is at 983 nm,and the absorption rate is as high as 99.73%,basically achieving perfect absorption.According to the calculated electric and magnetic field distribution maps,it can be obtained that the strong absorption is mainly due to the coupling between the surface plasmon polarization and the air groove mode.Finally,the effects of polarization,oblique incidence and structural parameters on the performance of the absorber are also studied.2.In the infrared band,a three-dimensional elliptical open-resonance ring structure metamaterial absorber is designed using metallic silver.Through simulation,the absorber achieved dual-frequency narrow-band absorption in the nearinfrared band,the first absorption peak is at 184.34 THz,the second absorption peak is at 293.14 THz,and its absorption rate is above 96%,and the quality factors(Q)of the two absorption peaks are calculated,which are as high as 51.82 and 94,respectively.According to the simulation calculation,the magnetic field distribution map and energy loss distribution map of the absorber are obtained.The physical mechanism of the dual-frequency narrow-band perfect absorption is explained.At the same time,the influence of structural parameters on the absorbing performance of the absorber is also studied.Finally,the dual-frequency narrowband absorber is studied in terms of refractive index sensing.It is found that the sensitivity of the dual-frequency narrowband absorber reach 1621nm/RIU and 970nm/RIU,and the figure of merit(FOM)are 51.54 and 89.04.In this paper,the metamaterial absorbers designed with metal materials is verified through theoretical analysis and numerical simulation methods,and its feasibility and effectiveness in engineering applications are confirmed.It can be selected according to the needs of the actual environment,with potential application value.