Dual-mode liquid-crystal element for polarization imaging with an extended depth of field

Extended depth-of-field (DoF) imaging enhances longitudinal clarity but traditionally fails to record polarization information. Here, we propose a liquid-crystal Pancharatnam–Berry (PB) phase element that extends DoF while sensing polarization ellipticity. Leveraging cubic-phase-induced defocus-insensitive point spread functions, a 10 cm DoF is achieved in a 10-cm-focal-length 4f system. Linear PB phases enable spin-orbit interactions to detect polarization states, overcoming irreversible polarization loss in conventional methods. This dual-functionality system integrates DoF extension with polarization sensing, enhancing multidimensional imaging capabilities and holding promise for advancing machine vision, microscopic imaging, and optical detection by merging depth clarity with polarization-based object differentiation.