Silicon Nitride Metalenses for Close-to-One Numerical Aperture and Wide-Angle Visible Imaging

SiN is an emerging semiconductor for integrated optoelectronics, due to its ultralow loss in the visible region. Developing a high-performance SiN metamaterial lens (metalens) is attractive for on-chip optical devices, but is held back by technical challenges in nanofabrication. The authors report the experimental realization of a SiN metalens that is 1 cm across and 695 nm thick, by means of CMOS-compatible fabrication. With high-quality, wide-angle visible imaging, these results point to the miniaturization of lenses for optical fibers, microendoscopes, and smart phones, as well as applications in all-sky telescopes, large-angle beam shaping, and near-eye imaging.