Broadband, Transmissive, and Cascadable Terahertz Programmable Metasurface
Hangbing Guo, Benwen Chen, Yuan Li, Weili Li, Shihe Yang, Sheng Wang, Wei Zhu, Jingbo Wu, He Ma, Xinping Zhang, Caihong Zhang, Kebin Fan, Huabing Wang, Biaobing Jin, Jian Chen, Peiheng Wu
Abstract
Programmable metasurfaces have emerged as versatile tools for optical information processing across a wide range of frequencies. The existing designs in the terahertz band primarily work in reflective modes with a narrow bandwidth, leading to a complex optical path and challenges in integrating with other optical components. Here, we proposed a transmissive programmable metasurface based on a vanadium dioxide film transferred onto an ultrathin substrate and demonstrated its capability for matrix operations in a dual-layer cascaded configuration. The metasurface consists of 8 × 8 independently electrically addressable pixels, achieving an insertion loss of less than 3 dB in the ON state at frequencies below 1 THz. It exhibits a modulation depth exceeding 75% from 1.01 to 1.80 THz and greater than 50% in the OFF state across 0.51-1.80 THz, corresponding to a modulation bandwidth of up to 111%. The device can also operate under bent conditions. The proposed transmissive programmable metasurface, with its optically thin thickness, ease of stacking, and efficient transmission, presents a promising pathway for the realization of compact, high-efficiency, and multifunctional optical systems.