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

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.