Metasurface significantly enriches the light-matter interaction and promotes the development of planar optics. In recent years, with the rapid advancements of terahertz (THz) technology, THz devices with switchable and reconfigurable functions have been intensively pursued. Liquid crystal (LC), a unique soft matter that combines the fluidity of liquids and the order of crystals, is now indispensable in displays and spatial light modulations. LC is integrated with metasurfaces to realize dynamic THz devices and apparatuses as well. This review summarizes the research progress in LC based THz metadevices in three different respects: LC planar THz devices, LC integrated metal metasurfaces, and LC integrated dielectric metasurfaces. Various technologies for fabrications of LC microstructures and integrations of LCs with metal or dielectric metasurfaces are presented. The obtained LC metadevices exhibit excellent responsiveness to external stimulus such as electric fields, magnetic fields, heat, and light. By this means, the amplitude, frequency, phase as well as polarization of THz waves are dynamically manipulated. The LC based tunable THz metadevices will significantly improve THz applications in imaging, communication, and sensing.

中文翻译：

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基于液晶的可调谐太赫兹超元器件


超表面显著丰富了光-物质相互作用，促进了平面光学的发展。近年来，随着太赫兹 （THz） 技术的快速发展，具有可切换和可重构功能的太赫兹器件受到广泛追捧。液晶 （LC） 是一种独特的软物质，它结合了液体的流动性和晶体的有序性，现在在显示器和空间光调制中不可或缺。LC 与超表面集成，以实现动态太赫兹器件和装置。本文从三个不同方面总结了基于 LC 的太赫兹超构器件的研究进展：LC 平面太赫兹器件、LC 集成金属超表面和 LC 集成介电超构表面。介绍了用于制造 LC 微观结构以及 LC 与金属或介电超表面集成的各种技术。所获得的 LC 超元器件对电场、磁场、热和光等外部刺激表现出优异的响应能力。通过这种方式，可以动态控制太赫兹波的振幅、频率、相位和极化。基于 LC 的可调谐太赫兹超元器件将显著改善太赫兹在成像、通信和传感方面的应用。