Large-Scale Metasurfaces Based on Grayscale Nanosphere Lithography

Metasurfaces, based on subwavelength structuring, provide a versatile platform for wavefront manipulation in an ultrathin form factor. The manufacturing of metasurfaces, however, generally requires fabrication techniques, such as electron-beam lithography, that are not scalable. One alternative is the use of ultraviolet steppers, but these require significant capital investment and there are challenges in handling the large mask sizes that metasurfaces demand due to the structuring density. In this paper, we propose and demonstrate a novel manufacturing method based on self-assembly of nanospheres in combination with grayscale lithography. This technique enables large-scale metasurfaces with nonperiodic phase profiles while being cost-effective. As a proof of concept, we demonstrate a series of large-scale (1 mm diameter) metalenses demonstrating diffraction-limited focusing as well as holograms. This approach could open new doors to cost-effective and large-scale fabrication of a wide range of metasurface-based optics.

Automated summary

The paper proposes a novel manufacturing method for metasurfaces based on self-assembly of nanospheres combined with grayscale lithography, enabling large-scale metasurfaces with nonperiodic phase profiles in a cost-effective manner. This approach demonstrates diffraction-limited focusing and holograms on a series of large-scale metalenses, potentially opening new doors for cost-effective and large-scale fabrication of a wide range of metasurface-based optics.