Polarization‐Multiplexed Double‐Helix/Airy Metalens for Depth‐Resolved Texture Imaging With Extended Depth‐of‐Field

Abstract

ABSTRACT Simultaneously acquiring high‐fidelity texture and reliable depth cues over an extended working range remains a central challenge for compact passive imaging systems. Conventional point‐spread‐function (PSF)‐engineered optics usually rely on a single optical response to perform both axial encoding and image formation, creating an inherent trade‐off between depth discriminability and lateral image quality. Here, we demonstrate a polarization‐multiplexed multifunctional metalens that decouples depth encoding from texture observation within a single titanium dioxide planar device. By jointly designing propagation and Pancharatnam–Berry geometric phases, the two circular polarization channels are assigned to double‐helix (DH) PSF response for depth encoding and Airy PSF for extended‐depth‐of‐field (EDOF) texture observation, respectively. The Airy‐channel target scale serves as an internal reference for depth‐feature extraction. The DH‐derived depth further guides Airy‐PSF selection and enables non‐blind texture deconvolution. Experiments on multi‐depth letter targets and textured objects demonstrate depth‐resolved texture recovery over a 20–70 cm working distance, with improved contrast, sharpness, and structural similarity. This function‐decoupled DH/Airy architecture uses complementary PSF channels to mitigate the trade‐off between depth discriminability and lateral image quality, providing a compact optical‐computational strategy for depth‐aware EDOF imaging in miniaturized metalens systems.