Vectorial Generalized Snell's Law‐Enabled Differentiable Ray Tracing for Large‐Aperture Visible Achromatic Hybrid Meta‐Optics

Abstract

Single metalenses are limited by their physical constraints, precluding themselves from achieving high numerical aperture across a wide visible spectral band in large‐aperture applications. A hybrid system that integrates a metalens with a refractive lens can address this issue, yet previous designs lacked sufficient flexibility. Here, by deriving the vectorial generalized Snell's law, a new paradigm is introduced for the hybrid metalens design based on differentiable ray tracing. Through joint optimization of the phase distribution of the metalens and refractive lens parameters, the system achieves achromatic performance within the broad spectral range of 420–680 nm, with an 8 mm aperture and a numerical aperture (NA) of 0.32. Compared to a single aspheric refractive lens, the design reduces chromatic aberration by 83% and provides high‐quality full‐color imaging. This approach bridges the gap between meta‐optics and refractive optics, advancing the development of metalenses in the realms of optical design and computational imaging.