Regionally‐Composite Phase Metalens: Breaking the Field‐of‐View Limitation for High‐NA Imaging

ABSTRACT Breaking the inherent trade‐off between the field of view (FOV) and the numerical aperture (NA) constitutes a fundamental challenge for developing next‐generation ultra‐compact imaging systems in virtual reality and mobile devices. Here, a regionally‐composite phase metalens (RCPM) design strategy based on physical‐structure modulation is proposed. By partitioning the metalens into targeted zones with phase profiles optimized for specific incident angles, this single‐plane architecture achieves enhanced focusing efficiency across both a high NA and a wide FOV, breaking through the inherent efficiency limitations of conventional metalenses. To validate this concept, a 2‐mm‐diameter metalens with an NA of 0.8 is fabricated. Experimental characterization reveals that the RCPM achieves an absolute focusing efficiency enhancement of nearly 20 percentage points at normal incidence compared to standard quadratic designs, effectively mitigating the aperture truncation issue, and is polarization‐insensitive. Furthermore, imaging demonstrations validate the sub‐micron resolving capability of the RCPM by successfully resolving 0.775 µm features at normal incidence, while maintaining robust wide‐field imaging performance up to a large oblique incident angle of 45°. This work can be extended to other materials and diverse wavefront manipulation needs, paving the way for ultra‐compact architectures in high‐integration imaging systems for machine vision, VR, and computational imaging.