基于局部表面等离子体激元的共振增强超材料吸收器的吸收性质

摘要

提出了一种在150～ 165 THz区域内的具有单峰吸收特性的高性能超材料吸收器.设计的吸波器包含两个阵列:双金属颗粒阵列和双空气孔阵列.金属层的阻尼常数在模拟中被优化.发现在模拟中使用2.3倍的阻尼常数时,可以获得最大吸收率96％.吸收峰由局域表面等离子体(LSP)模式共振激发.为了揭示共振电磁机理,进行了两组模拟,研究结构参数变化对共振吸收峰的影响.发现随着垂直距离V的增加,吸收峰被增强,当V=160 nm时,获得新的吸收带.在第二次模拟中,对于水平距离H的增加,吸收峰也增强,并且当H=190 nm时获得另一个新的吸收带.电场强度分布结果表明LSP模式的激发和LSP模式之间的耦合效应导致吸收峰增强现象.%In this paper,we present a single peak absorption characteristic of high performance metamaterial absorber in 150 ～ 165 THz region.The designed absorber contains two arrays:a dual metallic particles array and a dual air holes array.The damping constant of metal layer is optimized in simulations.It is found that the maximum absorption rate 96％ can be obtained when using 2.3 times of damping constant in simulations.The absorption peak is excited by the localized surface plasmon (LSP) modes resonance.In order to reveal the resonant electromagnetic mechanism and research the effects of structural parameters variations on the resonant absorption peak,two sets of simulations were carried out.It was found that with increasing the vertical distance V,the absorption peak is enhanced and a new absorption band is achieved when V =160 nm.In the second simulations,for the increase in horizontal distance H,the absorption peak is also enhanced and another new absorption band is achieved when H =190 nm.Electric field intensity distribution results show the excitation of LSP modes and the coupling effect between LSP modes lead to the absorption peak enhanced phenomenon.