High-Damage-Threshold Metasurfaces with Apertures Exceeding 100 mm Fabricated by Spatiotemporally Shaped Femtosecond Laser

Metasurfaces offer powerful capabilities for light field manipulation, yet their practical deployment in high-power laser systems remains limited by low laser-induced damage thresholds (LIDTs), small apertures, and low absolute conversion efficiency (ACE). Here, we demonstrate a circular Airy-like beam generator and a quarter-wave plate with high LIDTs and large apertures, which are realized through spatiotemporal and polarization co-shaping femtosecond-laser processing. By combining a temporally delayed longitudinal multi-foci strategy in the spatiotemporal domain with elliptical polarization modulation, we achieved a 22.5-fold increase in fabrication efficiency. The fabricated metasurfaces feature large apertures up to 102 mm, with a low temperature rise of only 4.38 °C under continuous laser irradiation for 100 s at a high-power density of 24 kW/cm2 and a high LIDT of 77 J/cm2 for pulsed laser (1064 nm, 6 ns). Besides, the metasurface achieves an exceptionally high ACE exceeding 99.57% after a dual-sided anti-reflection coating. Such large-aperture, high-LIDT, and high-ACE metasurfaces offer new opportunities for high-power applications, including inertial confinement fusion, laser energy transmission, and more.