Deep-Ultraviolet AlN Metalens with Imaging and Ultrafast Laser Microfabrication Applications

Deep-ultraviolet (DUV) light is essential for applications
including
fabrication, molecular research, and biomedical imaging. Compact metalenses
have the potential to drive further innovation in these fields, provided
they utilize a material platform that is cost-effective, durable,
and scalable. In this work, we present aluminum nitride (AlN) metalenses
as an efficient solution for DUV applications. These metalenses, with
a thickness of only 380 nm, deliver DUV focusing and imaging capabilities
close to the theoretical diffraction limit. Leveraging their robustness
to intense ultrafast laser irradiation, we demonstrate successful
DUV ultrafast laser direct writing of microstructures on a polymer
film and silicon substrate. These results underscore the significant
promise of advancing photonic technologies in this critical wavelength
regime.