对THz器件远场、近场的控制，尤其是主动可调，在THz成像、传感和探测等诸多领域具有极大需求。液晶具有宽带可调特性且种类丰富，在可见光（显示）等波段有成熟的技术积累，使得液晶THz器件具有很多优势，但其可调范围小、响应速度慢等严重阻碍了实际应用。本项目将传统THz液晶器件与超材料/石墨烯相结合，利用1)在THz波段具有大双折射、快速响应等优良特性的液晶材料、2)具有局域场增强与亚波长分辨本领的THz超材料、3)自主研发的少层多孔石墨烯THz透明电极，设计制备超紧凑的电控THz功能器件，实现大范围、快速调控THz远场、近场。进一步充分利用光控取向技术精确控制液晶在超材料、石墨烯微区域上取向，深入研究THz远场和近场的变化规律，建立内在联系机制。该项目的实施将为基于液晶的新型THz成像、传感和探测器的研发提供理论依据与技术支持。

Versatile devices which can actively manipulate the terahertz (THz) far-field and near-field are in high demand for THz imaging, sensing and detecting. Liquid crystals (LCs) have proven to be a perfect means of fulfilling these needs in the visible and telecom bands. It is also a very promising candidate for the new platform of THz devices. Currently, LC-based THz tunable components have been widely proposed. Unfortunately, the narrow tunable range and very slow response time hamper their further development in practical applications. Here, a strategy to realize widely and fast tunability is proposed: 1) THz high-birefringence liquid crystal, 2) THz metamaterial with near-field enhancement and sub-wavelength resolution, 3) Few-layer porous graphene THz transparent electrode. By integrating the advantages of the three kinds of materials, it is expected to enhance the tunable range and improve the response time. By controlling the LC’s alignment in micro domain of metamaterial and graphene through a non-contact photo-alignment technique, this project would systematically research on the interaction between LC and THz waves to bridge the THz near-field and far-field. It will provide the theoretical and technological support for newly LC based THz imager, sensor and detector.