基于先进钒钛相变薄膜的太赫兹波束操控动态阵列器件研究

太赫兹波束操控动态阵列器件是波束扫描和近场超分辨成像系统的核心器件，在无线通信、成像雷达和生物医学等领域具有重要的应用价值，也是本领域公认的国际性难题。为了解决传统电控方式难以在太赫兹频段实现大视场扫描和大阵列编码问题，本项目提出运用钒钛相变薄膜光致半导体相与金属相之间的相变物理过程与二维人工微结构表面相位梯度分布变化机制和波阵面数字编码机制相结合，实现太赫兹波束高效、超快调控。重点突破光致钒钛相变薄膜超快局域相变机制与性能优化，研制在太赫兹频段具有高效、超快响应能力的钒钛相变薄膜；研制出工作频率大于0.3THz，波束扫描精度小于5度、扫描范围大于±45度的平面波束扫描器件和128×128二维数字编码的太赫兹波前调控器件；完成太赫兹波束扫描实验系统和近场超分辨成像实验系统的构建和验证实验。形成太赫兹波束操控动态阵列器件从材料制备、器件研制以及系统联试验证一体化研发能力。

As a pivotal component of beam scanning and near-field super-resolution imaging systems, the terahertz dynamic beam-manipulation array devices exert veritable application value in wireless communication, radar imaging, life science, and other fields. Confronting formidable challenges with a conventional electrically-controlled manner, the implementation of wide-view-field beam steering and sizable coding arrays has been widely recognized as a dilemma by the THz community. To address the issue, this research proposes to attain fast and efficient terahertz beam manipulation by applying both the phase-gradient-distribution mechanism and digital wavefront-coding strategy on vanadium-titanium implanted metasurfaces, whereby dynamically employing the optically-regulated semiconductor-to-metal phase transition of the vanadium-titanium film. Starting with the endeavor on a salient breakthrough of the ultrafast photo-induced phase-transition mechanism and related performance optimization of the vanadium-titanium thin films, the research is organized into three progressive objectives as follows. Within the device-level theme, the core objective is to develop high-efficiency and ultrafast vanadium-titanium phase-transition-film materials in the terahertz range, planar beam-scanning devices with operation frequencies over 0.3 THz, angular scanning resolution under 5 degree, and a scan range over ± 45 degrees, and two-dimensional digital coding terahertz wavefront devices with 128 × 128 arrays. Furthermore, for the sake of prototype corroboration, the experimental platform for terahertz beam scanning and nearfield super-resolution imaging will be built and followed by verification experiments. Ultimately, it is expected that an integrated research and development chain of the terahertz dynamic beam-manipulation array devices will be established, including from material processing, device development to system validation.