树叶状红外频段完美吸收器的仿真设计

Numerical simulation of leaf-shaped metamaterial absorber at infrared frequency

设计了一种由树叶状金属薄膜-介质层-金属薄膜构成的低剖面完美吸收器模型.通过对金属介电性能采用Drude定理,仿真发现调节结构参数可在红外通讯频段几乎达到完美吸收(吸收率为99.5%),并且在某些特定的结构参数下可以同时实现双频段的完美吸收(其吸收率分别达到99.67%和97.13%),这在某种意义上展宽了吸收频带,对红外吸收器的设计与应用极为有利.最后探索了叶颈宽度变化对双频吸收峰位置的影响,以便对双峰吸收进行调频操作.这种红外频段的超材料吸收器具有结构简单、吸收效率极高、工作频段宽等优点.

We present a perfect metamaterial abosorber composed of metallic leaf-shaped cells,dielectric substrate and metallic film.Based on the metallic Drude principle,this structure can realize an perfect absorptivity of 99.5%at the infrared communication frequencies with appropriate geometric parameters.Moreover,this structure can simultaneously achieve perfect absorptions at two infrared frequencies with the maximal magnitudes of 99.67% and 97.13% respectively,which effectively broadens the bandwidth of absorptivity, thereby benefiting the design and the application of absorber at the infrared frequencies.Afterward,the effects of the neck width on the position of the double absorptivity peak are investigated,and expected to be used in frequency modulation.The model proposed in this paper has a series of advantages such as simple structure,high absorptivity and broad operating bandwidth.