Space‐Decoupling Nonlocal Metasurfaces for Resonant Wavefront‐Shaping Metaoptics

ABSTRACT Optical metasurfaces leverage localized meta‐unit responses for broadband wavefront control and harness nonlocal interactions across extended structures to support narrowband resonances. However, integrating both functionalities within a single metasurface remains a significant challenge. Current strategies typically involve trade‐offs between local phase control and nonlocal resonance, leading to compromises in key performance metrics such as efficiency, Q ‐factor, and design flexibility. These limitations significantly hinder the development of resonant wavefront‐shaping meta‐optics. Here, we propose a space‐decoupling nonlocal metasurface that achieves complete decoupling between local phase modulation and nonlocal resonance responses. Such devices can obtain arbitrary desired resonances by tailored nonlocal metasurfaces and spatially programmed wavefront control through silica‐substrate‐embedded geometric phase modulation. A theoretical polarization conversion efficiency in transmission can attain 100%, surpassing the theoretical 25% limit associated with nonlocal wavefront‐shaping metasurfaces. As a proof of concept, we designed and experimentally demonstrated a metalens with triple‐resonant responses in the near‐infrared band, which provides a maximum transmission polarization conversion efficiency of 35.5%. This work offers a universal pathway for resonant wavefront‐shaping metaoptics and can effectively advance emerging applications such as AR displays and bioimaging.