Deep-Ultraviolet AlN Metalens with Imaging and Ultrafast Laser Microfabrication Applications
Yu Chieh Peng, Yu Jie Wang, Kuan-Heng Chen, Yu Hung Lin, Haruyuki Sakurai, Hsueh-Chih Chang, Cheng-Ching Chiang, Ruei‐Tzu Duh, Bo-Ray Lee, Chia‐Yen Huang, Min‐Hsiung Shih, Ray‐Hua Horng, Kuniaki Konishi, Ming Lun Tseng
Abstract
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.