High-Contrast Transmissive Terahertz Programmable Metasurface Based on Liquid Crystal

Abstract

Programmable metasurfaces at terahertz (THz) frequencies hold a vast potential for applications in biomedical imaging, security screening, and wireless communication. However, the limited on–off ratio of existing devices restricts their applications, which demand high target distinguishability or precise modulation. Here, we demonstrated a liquid-crystal-based transmissive programmable metasurface that achieves an on–off ratio of up to 16. To enable scalable integration, the hardware complexity in large-array devices is effectively reduced, validated in a 16 × 16 pixel configuration. We employed the fabricated sample in compressive sensing imaging experiments, where the transmissive design simplified the optical path with its high on/off ratio, significantly enhancing image reconstruction quality. This work presents a compact and large-scale array solution for advanced THz imaging applications.