32-State Liquid Crystal Programmable Metasurface for Terahertz Phase Manipulation
Guozhen Zhang, Kai‐Wen Li, Lu Xu, Jun Yang, Zhiping Yin, Hongbo Lu, Guangsheng Deng, Ying Li
Abstract
This paper presents a programmable metasurface utilizing liquid crystals (LC) for terahertz applications, featuring a multi-state phase shifter. Unlike a reflective metal layer, metallic grating is used in the metasurface unit. Nematic liquid crystal material is filled between the grating and the resonant structure. The grating electrodes in the unit are segmented into 5 groups. The bias voltage applied to different gratings allows the deflection of the liquid crystal molecules in the corresponding regions. The encodings in the experiment represent the states of the five sets of electrodes. The 32 switchable encodings of the phase shifter are evaluated in the experiments. At 393.2 GHz, the phase of the reflected wave varies between 0° and 235° depending on the different encodings. This study introduces a practical approach for implementing multi-bit programmable metasurfaces, facilitating the construction of reconfigurable intelligent metasurfaces in the terahertz frequency bands. This manipulation method could also be applied to other LC-based metasurface devices.