Amplitude‐Only Metasurface Holography for Precise Near‐Field Plane‐Wave Synthesis

ABSTRACT Metasurface holography plays a crucial role in versatile and compact electromagnetic (EM) devices through flexible multi‐dimensional field control. However, conventional phase‐dominated paradigms, including phase‐only and complex‐amplitude modulation, struggle with the intrinsic inter‐element coupling effects within metasurface arrays, significantly hindering high‐precision wavefront shaping. Here, an amplitude‐only metasurface framework with inherently low coupling effects is proposed for high‐precision near‐field plane‐wave synthesis. A comprehensive analysis of multiple coupling effects within metasurface systems is conducted, revealing the general distribution characteristics of inter‐element coupling effects. Independent of specific implementation mechanisms, amplitude modulation is validated to exhibit superior robustness to coupling errors compared with phase modulation. As a proof of concept, comparative experiments on near‐field plane‐wave synthesis are conducted based on a specially designed high‐resolution diffractive neural network. The amplitude‐only metasurfaces achieve substantially more accurate complex‐amplitude wavefront shaping, with magnitude and phase fluctuations strictly below 1 dB and 10°, respectively. A quantitative agreement between experiments and simulations further validates the feasibility of the proposed amplitude‐only metasurface framework. The findings provide a straightforward and robust implementation route for advanced optical and microwave systems with precise EM control and are expected to inspire a novel EM manipulation paradigm.