基于双层VO_(2)的可调谐宽带太赫兹超材料吸收器

Tunable wideband terahertz metamaterial absorber based on double-layer VO_(2)

基于VO_(2)的相变特性,提出一种具有宽带特性的太赫兹超材料吸收器,包括2层VO_(2)图案、2层聚酰亚胺介电层和1层金属反射层,共5层结构。对吸收器的吸收特性、电场分布和可调谐特性进行仿真分析,结果表明,所设计的吸收器吸收率大于90%的带宽为2.56 THz。该吸收器将2层结构相同但尺寸不同的周期单元堆叠,有效扩展了带宽;且通过控制VO_(2)从绝缘态到金属态的相变,可以实现吸收率的连续调谐。通过研究不同偏振角及入射角条件下所设计超材料吸收器的吸收性能发现,该吸收器具有偏振无关、在较大入射角入射时吸收不敏感特性。所设计的吸收器有望在太赫兹通信、成像和探测器等领域得到广泛应用。

A wideband terahertz metamaterial absorber is proposed based on the phase transition properties of VO_(2),which consists of two VO_(2) pattern layers,two polyimide dielectric layers and a metal reflector layer.The absorption characteristics,electric field distribution and tunability of the absorber are simulated and analyzed,and the results show that the bandwidth of the designed absorber with an absorption rate of more than 90%is 2.56 THz.The absorber stacks two layers of periodic cells with the same structure but different sizes,effectively extending the bandwidth.Moreover,by controlling the phase transition of VO_(2) from the insulating state to the metallic state,the absorptivity can be continuously adjusted.In addition,by studying the absorption performance of the designed metamaterial absorber under different polarization angles and incident angles,it is found that the absorber is polarization independent and absorption insensitive at large incident angles.The designed absorber is expected to be widely used in areas of terahertz communication,imaging and detector.