基于二氧化钒宽、窄带可切换的双功能超材料吸收器研究

本文提出了一种宽、窄带可切换的双功能超材料吸收器.在超材料吸收器的结构中,引入了相变材料二氧化钒(VO2),仅利用单个可切换超表面就能实现不同的功能,其不同功能之间的相互转换通过VO2绝缘态和金属态之间的可逆相变特性实现.当VO2处于金属态时,设计的结构可以看作一个超材料宽带吸收器.仿真结果表明,在1.55THz至2....

Wide and narrow band switchable bi-functional metamaterial absorber based on vanadium dioxide

A wide-band and narrow-band switchable bi-functional metamaterial absorber is presented in this paper.The phase change material vanadium dioxide(VO₂)is introduced in the structure of the metamaterial absorber,and different functions can be achieved by using only a single switchable metasurface.The mutual conversion of different functions is realized by the reversible phase transition between the VO₂insulating state and the metal state.When VO₂is in metallic state,the designed structure can be regarded as a metama-terial wide-band absorber.The simulation results show that the absorption is over 98%in the frequency range of 1.55 THz to 2.21 THz.When VO₂is in the insulating state,the structure acts as a narrow-band absorber,and the absorption at resonance frequencies of 2.54,2.93 and 3.34 THz is over 95%.In addition,the effect of geometric parameters on the absorption of metamaterial absorber is discussed.Because of the symmetry of the element structure,the absorber is insensitive to the polarization when the electromagnetic wave is vertic-ally incident,and it can keep good absorption performance with the large incident angle.Therefore,the switchable bi-functional metamaterial absorber proposed in this paper can be widely used in terahertz modulation,thermal emitters and electromagnetic energy acquisition,etc.