Programmable coding metasurface controlled by ultraviolet light-patterns

Abstract

Combining multiple physical fields with programmable metasurfaces in realistic scenarios is a hot topic. There are numerous studies on controlling metasurfaces using light-field, thermal fields, and so on. Due to its excellent penetration and invisibility, ultraviolet (UV) has benefits that conventional light does not possess. However, previous works that apply UV-light to metasurfaces and modulate electromagnetic (EM) waves using UV-light sensing can only sense very few points. This paper proposes a UV-sensing metasurface integrated with an 8*8 sensor array and can achieve a complicated UV-information input and more complicated EM-filed manipulation, including dual-beam, chess-board patterns, and RCS-reduction. By assembling a UV-sensor and an embedded PIN diode on each metasurface supercell, each supercell (2*2 elements) not only can independently sense and feed back the change of UV-light intensity, but also be programmed for diverse EM functions. After elaborate simulation and experiment, the experimental outcomes are in good agreement with the simulative outcomes, which verifies the feasibility of the scheme. Such matrix UV-light field input builds a new interactive channel with electromagnetic information, which is suitable for application scenarios with flexible requirements for communications and imaging.