biostudies-literatureUnknown12(8)Jung JMetalenses have potential to replace various bulky conventional optical elements with ultrathin nanostructure arrays. In particular, active metalenses with reconfigurable focusing capability have attracted considerable interest from the academic and industrial communities. However, their tuning range is currently restricted by limited material properties and fabrication difficulties. Here, a hybrid optical system capable of three-dimensional relocation of a focal spot is proposed and experimentally demonstrated. The system comprises a mechanically actuated passive metalens doublet that can be easily fabricated with commonly available materials and processes. An incident laser can be focused to a desired point in three-dimensional space simply by rotating two metalenses or changing their seNanophotonics (Berlin, Germany)1373-1385https://www.ebi.ac.uk/biostudies/studies/S-EPMC11501995biostudies-literatureThree-dimensionally reconfigurable focusing of laser by mechanically tunable metalens doublet with built-in holograms for alignment.PMC11501995Jung JKim HShin JfalseThree-dimensionally reconfigurable focusing of laser by mechanically tunable metalens doublet with built-in holograms for alignment.Metalenses have potential to replace various bulky conventional optical elements with ultrathin nanostructure arrays. In particular, active metalenses with reconfigurable focusing capability have attracted considerable interest from the academic and industrial communities. However, their tuning range is currently restricted by limited material properties and fabrication difficulties. Here, a hybrid optical system capable of three-dimensional relocation of a focal spot is proposed and experimentally demonstrated. The system comprises a mechanically actuated passive metalens doublet that can be easily fabricated with commonly available materials and processes. An incident laser can be focused to a desired point in three-dimensional space simply by rotating two metalenses or changing their se2023-01-01T00:00:00Z2023 Apr2025-04-04T01:15:44.791Z2025-04-04T01:15:44.791ZS-EPMC115019953963460310.1515/nanoph-2022-0634