Ultra‐High Contrast Terahertz Modulation and Pixelated Display Based on VO 2 Metasurface

Abstract

ABSTRACT The development of high‐performance, dynamically reconfigurable devices is important for advancing Terahertz (THz) technology. Vanadium dioxide (VO 2 ), a metal‐insulator transition oxide with a near‐room‐temperature critical point, is promising for infrared (IR) and THz modulation. However, achieving simultaneous high transmission in the ON state, deep suppression in the OFF state, and electrical programmability in a broadband THz device remains challenging. Here, we propose an electrically controlled VO 2 THz metasurface that overcomes these limitations. Our design yields an ultra‐high transmission switching ratio of 10 000 at 0.88 THz in simulation and a broad bandwidth from 0.2 to 1.3 THz (switching ratio >100). It maintains a high transmission of 0.85 in the insulating state while suppressing transmission to ∼10 −4 in the metallic state, corresponding to a modulation depth exceeding 99.9%. Based on the multiple THz transmission levels, we demonstrate a proof‐of‐concept reconfigurable pixelated display, which highlights the potential of our high‐contrast metasurface for THz spatial light modulation applications. By integrating our VO 2 metasurface with a Ni/Pt bilayer for electrical gating of spintronic THz emission, a compact, amplitude‐modulated THz source is fabricated. Our work establishes a robust platform for high‐performance, programmable THz devices, bridging the gap between static meta‐materials and dynamic photonic systems for imaging, communications, and integrated applications.