Dual-polarization metalens with dynamically reconfigurable focal position in three dimensions based on the Moiré effect

Zoom lenses are essential for optical imaging applications. The development of metasurfaces offers an approach to overcoming the complexities and bulkiness of conventional zoom systems. Most current tunable zoom metalenses only adjust focus in axial or transverse directions and lack multi-dimensional light field adjustment capabilities. In this study, a dual-polarization responsive three-dimensional zoom metalens based on the Moiré lens effect was designed. The metalens can provide continuous three-dimensional control of the focal point by adjusting the rotation angles of the three metasurfaces, achieving micrometer-level positioning accuracy across the entire spatial range. Furthermore, the metalens exhibits phase modulation characteristics associated with chirality. Specifically, when the incident light is excited in different circular polarization states (right-handed and left-handed), it produces a focal field distribution that depends on the polarization state. This is important for acquiring multi-dimensional information and enhancing target features in complex scenes. The metalens achieves axial zoom ranges of 1–6.5× for right handed circularly polarized light and 1–5.7× for left-handed circularly polarized light, with lateral deflection angles of ±12.5° and ±15.4°, respectively. The focusing efficiencies reach 65.2% and 67.1% for right- and left-handed circularly polarized light. This dual-polarization three-dimensional zoom metalens shows great promise for machine vision, microscopic imaging, and dynamic three-dimensional tracking, advancing multifunctional integrated optical systems.