Nanoprinted Geometric Phase Metalenses for Longitudinal Multifocusing with Achromatism, Polarization, and Intensity Manipulation

Longitudinal multifocal metalenses are pivotal for miniaturized multimagnification and 3D imaging, yet integrating tailored multifocal distributions, achromaticity, and polarization multiplexing in a single-layer design remains challenging. Here, we report a nanoprinted geometric-phase metalens that generates a longitudinally separated triple-wavelength multifoci, each wavelength producing three independent foci. The spatial overlap creates hybrid foci featuring a discrete-wavelength achromatic primary focus alongside companion foci, with fully tailorable polarization and intensity. Utilizing the optimized two-photon polymerization lithography, we achieve a 650 nm lattice period and an aspect ratio of ∼16, overcoming prior limits in phase sampling and diffraction loss. The fabricated metalens exhibits axial chromatic aberration below 1 μm and near-diffraction-limited focusing. Two prototypes are demonstrated for coherent red-yellow-green characterization and incoherent red-green-blue imaging, both enabling high-quality achromatic multimagnification. This strategy provides a compact, low-cost route toward integrated metalens optical systems.