Construction And Application Research Of Perfect Light Absorption Metamaterials Based On Plasmonic Resonance

Metamaterials are artificially designed materials that exhibit unique properties within a certain frequency range,which are distinct from naturally occurring materials.This makes metamaterials highly promising in various applications,especially in the field of absorbers.By carefully designing the composite material patterns and their arrangement,metamaterials can achieve perfect absorption,resulting in near-uniform absorption over narrow or wide bandwidths.Compared to traditional absorbers,metamaterial-based absorbers can achieve absorption performance closer to theoretical limits.Over the past decade,significant progress has been made in both experimental and theoretical studies on wideband metamaterial perfect absorbers,covering a broad spectral range,due to advancements in device fabrication and theoretical modeling.This article introduces three types of perfect absorbers based on metamaterials: an all-metallic absorber,an all-dielectric absorber,and a MIM-type absorber.The article also points out the current issues in perfect absorbers based on metamaterials.To address these issues,the finite-difference time-domain method was used to calculate and optimize the metamaterial absorbers to obtain the best design,providing guidance and reference for future research in this field:A novel truncated cone structure made of all-Ge material was designed and its superior performance compared to Si and Ga As materials was demonstrated.The optimal structure with broadband absorption effect was determined by comparing different top geometries of the truncated cone structure,including conical and cylindrical shapes.The effect of geometrical parameters,such as top radius,bottom radius,and height,on the absorption rate was studied by varying the simulation parameters and light source conditions.The results showed that the truncated cone structure has high absorption efficiency and tunability,and is less sensitive to incident angle and polarization,which makes it a promising candidate for practical applications.A pure dielectric metamaterial absorber with an ultra-thin planar structure(265nm)has been designed using germanium.By comparing the effects of different upper-layer structural unit sizes and different structural configurations,the optimal structure has been obtained.The working principle and absorption performance of the cross-stripe cavity trapezoidal structure metamaterial absorber have been further analyzed.The structure is composed of a symmetric arrangement of cross-stripe cavity trapezoidal arrays,so its absorption performance is independent of the incident light polarization.Compared with previous designs,the fabrication process of this structure is simpler,which has great reference value for designing high-performance photovoltaic devices.A frequency-selective optical absorber composed of an electro-optic waveguide cavity coupled with plasmonic microstructures is explored in this study.The absorber achieves wideband near-perfect absorption with spectral separation in the visible and near-infrared regions,as well as narrowband absorption peaks.Numerical simulations demonstrate that the absorber has a high spectral sensitivity of 7.1 nm/V under external voltage and maintains a high absorption efficiency,exceeding 97.5%.The findings of this study provide a new approach for differentiated light absorption and spectral manipulation,which can be achieved through the careful design of spatially geometrically correlated resonant media.