Huang Zhixiang, Wu Weipeng, Herrmann Eric, Ma Ke, Chase Zizwe A, Searles Thomas A, Jungfleisch M Benjamin, Wang Xi
Department of Materials Science and Engineering, College of Engineering, University of Delaware, Newark, DE, 19716, USA.
Department of Physics and Astronomy, College of Arts and Sciences, University of Delaware, Newark, DE, 19716, USA.
Front Optoelectron. 2024 May 27;17(1):13. doi: 10.1007/s12200-024-00116-4.
The non-ionizing and penetrative characteristics of terahertz (THz) radiation have recently led to its adoption across a variety of applications. To effectively utilize THz radiation, modulators with precise control are imperative. While most recent THz modulators manipulate the amplitude, frequency, or phase of incident THz radiation, considerably less progress has been made toward THz polarization modulation. Conventional methods for polarization control suffer from high driving voltages, restricted modulation depth, and narrow band capabilities, which hinder device performance and broader applications. Consequently, an ideal THz modulator that offers high modulation depth along with ease of processing and operation is required. In this paper, we propose and realize a THz metamaterial comprised of microelectromechanical systems (MEMS) actuated by the phase-transition material vanadium dioxide (VO). Simulation and experimental results of the three-dimensional metamaterials show that by leveraging the unique phase-transition attributes of VO, our THz polarization modulator offers notable advancements over existing designs, including broad operation spectrum, high modulation depth, ease of fabrication, ease of operation condition, and continuous modulation capabilities. These enhanced features make the system a viable candidate for a range of THz applications, including telecommunications, imaging, and radar systems.
太赫兹（THz）辐射的非电离和穿透特性近来使其在各种应用中得到采用。为了有效利用太赫兹辐射，具有精确控制功能的调制器必不可少。虽然最近的大多数太赫兹调制器操纵入射太赫兹辐射的幅度、频率或相位，但在太赫兹偏振调制方面取得的进展要少得多。传统的偏振控制方法存在驱动电压高、调制深度受限和带宽能力窄等问题，这阻碍了器件性能和更广泛的应用。因此，需要一种理想的太赫兹调制器，它能提供高调制深度，同时易于加工和操作。在本文中，我们提出并实现了一种由相变材料二氧化钒（VO）驱动的微机电系统（MEMS）构成的太赫兹超材料。三维超材料的模拟和实验结果表明，通过利用VO独特的相变特性，我们的太赫兹偏振调制器相对于现有设计有显著进步，包括宽工作频谱、高调制深度、易于制造、易于操作条件以及连续调制能力。这些增强特性使该系统成为一系列太赫兹应用（包括电信、成像和雷达系统）的可行候选方案。
