Design and optimization of metamaterial absorber based on metal patterned surface

• 1、School of Electronic Engineering,Beijing University of Posts and Telecommunications

Abstract：Subwavelength size metamaterial absorbers can achieve complex spectral responses through the design of micro and nano structures and are widely used in narrow band and wide band spectral absorption fields.Among them, the absorber working in 8-13 micron band has been widely concerned by researchers because of its application in the field of radiative cooling. The emphasis is on how to improve the average absorption of the absorber.In this paper, an optimal design method for multi-layer dielectric film metamaterial structure is proposed. Genetic algorithm is used to optimize the arrangement of the top metal patterned surface to achieve high efficiency subwavelength size metamaterial absorber.Numerical simulation results show that the average absorption of the optimized structure reaches 81.63%,which is 9.6% higher than before optimization. It is found that when the height of the metal pattern reaches 1.9 microns(aspect ratio 14.6), the average absorption of the structure can reach 95.83%. The design and optimization methods proposed in this paper have reference value in the design of multilayer dielectric film absorber and show a good application prospect in radiative cooling.

Keywords： radiative cooling metamaterial absorber genetic algorithm