Grating‐Lens Empowered Metafiber for Large‐Angle Light Collection With 3D Nanoprinted Structures

ABSTRACT Efficient and selective light coupling into optical fibers is essential for applications ranging from quantum photonics to biomedical imaging, yet conventional methods are constrained by limited efficiency and poor suppression of unwanted diffraction orders. This work introduces a novel metafiber that enables angle‐selective coupling into the fundamental mode of single‐mode fibers within the telecom spectral range between 1260 and 1650 nm using a compact 3D nanoprinted holographic grating lens integrated directly on the fiber end face. The approach combines a binary phase grating with a tailored kinoform‐type focusing profile and decouples the light‐collection area from the core size, enabling a significant increase in coupling efficiency and substantial suppression of the zeroth diffraction order. High coupling efficiencies of 10%–20 at large diffraction angles (40–60), along with strong zeroth diffraction order suppression factors up to 20 , are demonstrated, exceeding the performance of previously reported concepts related to light coupling at large incidence angles. The findings are supported by analytical modeling, numerical simulations, and automated optical characterization, and open new avenues for reconfigurable fiber‐based systems in quantum emitter collection, angular demultiplexing, and lab‐on‐fiber technologies.