Full-Stokes polarimetric detection infrared metalens with reduced coma under a large angle of incidence based on the quadratic phase

Infrared polarization detection offers rich contrast and feature-extraction capabilities beyond intensity or spectral imaging. However, conventional polarization detection setups rely on complex and bulky optical components. Recently, metasurfaces have attracted attention due to their capability of precise manipulation of electromagnetic waves on a two-dimensional interface. Nevertheless, metasurface-based polarimeters remain hampered by their low angular tolerance and severe coma under oblique illumination. In this work, leveraging on the quadratic phase, we propose and design an all-silicon infrared metalens with full-Stokes polarimetric detection capability that allows a large angle of incidence. Compared with metalens based on conventional hyperbolic phase, the proposed metalens operates effectively within an incidence angle of ±50° with minimal coma aberration. Furthermore, by matching the Stokes parameters calculated from the segmented channels with the incident polarization state, the full-Stokes polarimetric metalens can distinguish among various polarization states. Additionally, the angular range of correct polarimetric detection is determined as ±35°. The proposed device can be integrated into commercially mature photodetectors, offering potential applications in remote sensing imaging, biological diagnostics, machine vision, and related fields.