Scalable manufacturing of polarization-insensitive metalenses with high-uniform focal arrays in the visible (2503.09176v1)

Abstract: Multi-foci metalenses with uniform focal arrays attract special attention as they enable a single incident beam to focus on the same focal plane and share the identical numerical apertures. In this work, we demonstrate the scalable manufacturing of polarization-insensitive metalenses with high-uniform focal arrays in the visible. To overcome the limitations inherent in conventional imprint resins characterized by a low refractive index, hybrid meta-atoms are formed using the imprint resin itself, and a thin layer of titanium dioxide (TiO2) is deposited on it via atomic layer deposition (ALD) to increase the effective refractive index, enabling full phase coverage. We propose the gradient-descent-optimization strategy for phase retrieval of multi-foci metalens, which renders our design free from cross-talk and makes it feasible to achieve uniform focal arrays with flexible geometries. Based on this inverse-design scheme, the capability of nanoimprinted metalenses are explored by directly producing various focal arrays, including complex geometries such as square, rhombic lattices, as well as intact and defective rings. We envision this work may pave the way for various fields, including optical trapping, materials science, and quantum optics.