Polarization-insensitive achromatic wide-FOV metalens operating in the visible spectrum.

Single-layer metalenses are constrained by the dispersion of their meta-atoms, posing a significant challenge to simultaneously achieve polarization-insensitive, wide field-of-view (FOV), and achromatic imaging in the visible. Here, we propose a polarization-insensitive wide-FOV achromatic metalens based on complex topological meta-atoms. We construct a library of rotationally symmetric structures providing continuous phase coverage and high group delays. A multi-objective dynamic-weight particle swarm optimization algorithm is developed to synergistically optimize the phase profile at a reference wavelength and the group delay distribution, enabling wide-FOV phase matching across the visible band. Simulation results demonstrate achromatic and wide-FOV focusing exceeding 50° over 400-750 nm with a numerical aperture of 0.29 and average focusing efficiency > 40%. This work offers a viable route toward high-performance planar integrated imaging systems.