Large-Aperture, WFOV Broadband Achromatic Metalens Enabled by Forward Mapping Optimization and Hybrid Algorithmic Framework.

Achieving large aperture, wide field of view, and broadband achromatic imaging in the visible represents a critical challenge for advancing metalens toward practical applications. This work demonstrates a visible-spectrum metalens that simultaneously realizes a 4.584 mm aperture, a 100° field of view, and achromatic imaging over 400-680 nm. This study develops a forward mapping optimization (FMO) to overcome the dual bottlenecks of computational complexity and the need for global balance in aberration correction encountered by traditional point-by-point compensation approaches. This reduces computational complexity from O(N 2) to O(N). Simultaneously, a hybrid algorithmic framework is employed to significantly leverage the advantages of both global and local optimization algorithms. Simulation results demonstrate that this metalens achieves excellent achromatic imaging, with a maximum focal length deviation of less than 0.3%. The proposed approach features very low computational cost, requiring only a single 6-core, 12-thread computer. This method also exhibits rapid convergence and high computational precision. This research can be extended to other similar designs, laying the foundation for applications in novel smartphone cameras, robotic vision systems, VR/AR, and medical endoscopic imaging.