搜索

x
中国物理学会期刊

基于二氧化钒的太赫兹编码超表面

CSTR: 32037.14.aps.69.20200891

Terahertz coding metasurface based vanadium dioxide

CSTR: 32037.14.aps.69.20200891
PDF
HTML
导出引用
  • 由于受电子器件尺寸和加工技术的限制, 在太赫兹波段很少有主动调控的编码超表面. 为了提高太赫兹编码超表面的灵活性, 本文选择相变材料二氧化钒进行主动调控. 分析了二氧化钒相变前(绝缘态)和相变后(金属态)两种态对单元结构幅值和相位的影响, 设计出一种能够主动调控的基于二氧化钒的1 bit太赫兹编码超表面, 该结构由二氧化钒、聚酰亚胺和铝构成, 不仅可以实现编码超表面调节电磁波波束的基本功能, 而且对于同一编码序列还能通过温控二氧化钒在1.1 THz实现两种远场波束的切换, 同样对于同一编码序列也能通过温控在1.1 THz实现两种近场聚焦焦点的切换. 这种基于二氧化钒对相位的影响而设计的编码超表面为灵活调控太赫兹波提供一种新的途径, 将在太赫兹传输、成像和通信等方面有着重大的应用前景.

     

    Terahertz (THz) has the characteristics of non ionization, penetration, water absorption, high resolution, etc. It has shown an important application prospect in many fields, such as non-destructive testing, imaging and communication. However, THz is in the transition frequency band ranges from macro-electronics to micro-photonics, so, it belongs to the interdisciplinary field, forming the “terahertz gap” in electromagnetic wave. In recent years, with the continuous development and improvement of THz radiation source and detection technology, the THz modulation technology has gradually aroused the interest of researchers. Metamaterials with many properties that natural materials do not possess provide a common way to control THz. The two-dimensional structure of a metamaterial is called a metasurface. The coding metasurface encodes the phase digitally so that the electromagnetic wave can be regulated. It is proposed that it is first in the microwave band and then extended to the THz band. In the microwave band, the number, direction and amplitude of the far-field beams can be changed dynamically by programming, which is connected with the integrated circuit such as FPGA by using diodes, but due to the limitation of diode size and micro-nano manufacturing technology, the programmable metasurface in microwave band cannot be well used in THz band. In order to improve the flexibility of THz coding metasurface, in this paper we choose the phase change material vanadium dioxide (VO2) to active modulation coding metasurface. In this paper, we analyze the VO2’s insulating state before the phase transformation and metallic state after the phase transformation. Then designing an active control 1 bit coding metasurface by using the influence of the two states on the amplitude and phase of the unit structure, which is composed of VO2, polyimide and aluminum, can not only realize the basic function of coding metasurface adjusting the electromagnetic wave beams, but alsoimplement the switching of two kinds of far-field beams at 1.1 THz for the same coding sequence by thermal stimulated VO2. The coding metasurface also realizes the switching between two near-field focal points at 1.1 THz for the same coding sequence. Based on the effect of VO2 on the phase, this coding metasurface provides a new way to adjust and control the THz wave flexibly, and will have a great application prospect in THz transmission, imaging and communication.

     

    目录

    /

    返回文章
    返回