Design of a tunable Airy zoom metasurface based on the moiré effect

Dynamic control of Airy beam focusing is important for applications in optical manipulation, imaging, and laser processing. However, most metasurface-based Airy beam generators are statically designed, and tunability typically relies on mechanical translation, which limits system compactness and integration. Here, we propose a tunable Airy zoom metasurface based on the moiré effect. The device consists of two rotationally symmetric dielectric metasurfaces composed of titanium dioxide nanopillars. By encoding the Airy autofocusing phase and exploiting the rotational moiré modulation between the two layers, the output phase distribution can be continuously tuned through relative rotation, enabling dynamic control of the Airy beam focal position. Numerical simulations demonstrate that at a wavelength of 610 nm the focal length can be continuously tuned from 8 μm to 32 μm. Compared with conventional quadratic-phase moiré zoom metasurfaces, the proposed design preserves the nondiffracting characteristics of Airy beams while providing improved focusing efficiency and enhanced lateral resolution. This work offers a compact and mechanically simple approach for dynamically controllable metasurface optics and may facilitate the development of integrated and programmable photonic systems.