Broadband polarization-independent programmable near-field imaging metasurface based on liquid crystal

In this paper, a broadband polarization-independent programmable near-field imaging metasurface based on liquid crystal (LC) is proposed. First, an LC-based metasurface unit is designed to achieve polarization-independent amplitude 1-bit and 2-bit coding within the 0.374-0.416 THz frequency range. Then, according to the presented pattern, the amplitude coding metasurface units are arranged and manipulated in real time to achieve programmable near-field imaging. The near-field imaging based on the designed amplitude coding metasurface is studied using the electromagnetic simulation software CST. The results show that, based on the amplitude 1-bit and 2-bit coding metasurface, within the 0.374-0.416 THz frequency range, not only polarization-independent near-field binary imaging and near-field grayscale imaging can be achieved, but also different patterns can be manipulated in real time. Therefore, the designed amplitude coding metasurface achieves broadband polarization-independent programmable near-field imaging, enhancing the adaptability and flexibility of imaging, with potential application prospects in terahertz imaging technology.