High-Resolution Metalens Imaging Polarimetry

Imaging polarimeters find many critical applications in applications ranging from remote sensing to biological detection. Metasurfaces have been proposed as a compact approach for imaging polarimeters, but prior strategies suffer from low imaging resolution. Here, we propose an interleaved metalens configuration for polarization imaging where three-row metasurface units within a group individually interact with three pairs of orthogonal polarization channels. The optical paths between the object and adjacent three-row metasurfaces are nearly equal, allowing the construction of a metalens polarimeter with an unlimited numerical aperture (NA), which is beneficial for high-resolution polarization imaging. The metalens polarimeter fabricated by crystalline silicon nanostructures has a NA of 0.51 at 632.8 nm and achieves an imaging resolution of up to a 1.2-fold wavelength. Polarimetric microscopy experiments demonstrate that metalens polarimeters can realize high-resolution polarization imaging for various microscopic samples. This study offers a promising solution for high-resolution metasurface polarization imaging, with the potential for widespread applications.