Monolithic Multifocal Diamond Metalens for High-Power Laser Systems
Abstract
High-power laser systems increasingly rely on multi-beam processing to enhance manufacturing throughput. However, conventional multifocal systems remain constrained by bulky architectures, stringent alignment requirements, and susceptibility to laser-induced degradation under intense irradiation. Here, we demonstrate a monolithic multifocal diamond metalens with a 7.2 mm aperture that maintains exceptional thermal stability and power tolerance. The device employs high-aspect-ratio truncated-cone diamond nanopillars to generate two focal spots separated by 200 {\mu}m at a focal length of 4 mm. Under sustained 25 W pulsed-laser irradiation for 1 h, the diamond metalens exhibits a focal shift of only 25.5 {\mu}m, resulting in a maximum processing-depth variation of 33.2 {\mu}m during 4H silicon carbide (SiC) laser scribing, far below the 319.1 {\mu}m deviation observed for a commercial objective lens combined with a beam-splitting diffractive optical element (DOE). Even under extreme optical loading, the metalens withstands continuous-wave laser irradiation up to 8.25 kW for 30 s without structural degradation, while complementary pulsed testing yields a laser-induced damage threshold (LIDT) of 2.45 J/(cm^2) for diamond. This work broadens the operating envelope of transmissive meta-optics to extreme optical loads, opening new opportunities across high-power photonic systems.
Cite
@article{arxiv.2607.25264,
title = {Monolithic Multifocal Diamond Metalens for High-Power Laser Systems},
author = {Xiaoxuan Li and Xiaoyu Sun and Ce Li and Zhiqiang Xie and Fengjiang Liu and Boqu Chen and Ding Zhao and Kaikai Du and Min Qiu},
journal= {arXiv preprint arXiv:2607.25264},
year = {2026}
}