Generating all-optical frequency-multiplexed THz logic operations via fractal metasurfaces

Abstract

The realization of high-speed, low-power computing beyond conventional electronics demands new paradigms for optical logic processing. Here, we present a passive terahertz (THz) metasurface platform that enables intrinsic frequency-multiplexed logic operations within a single, compact device. By encoding logical inputs through orthogonal polarization states and exploiting the multi-resonant response of fractal H-shaped metastructures, the proposed system performs multiple logic operations simultaneously across the 0.2–2.0 THz band. Unlike existing approaches that rely on active tuning or sequential execution, our design achieves parallel logic functionality in a fully passive and multiplexed architecture. Experimental validation using THz time-domain spectroscopy confirms broadband operation with extinction ratios up to 9.09 dB and robust safety margins exceeding 10%. This work establishes a scalable route toward compact, energy-efficient, and all-optical parallel computing systems in the THz regime.