High-aspect-ratio, ultratall silica meta-optics for high-intensity structured light

Structured light and high-intensity ultrafast lasers are two rapidly advancing frontiers in photonics, yet their intersection remains largely unexplored. While ultrafast lasers continue to push the boundaries of peak intensities, structured light has enabled unprecedented control over light’s spatial, temporal, and polarization properties. However, the lack of robust optical devices, capable of bridging structured light with the high-intensity domain, has constrained progress in combining these directions. Here, we demonstrate high-aspect-ratio, ultratall silica meta-optics, which close this gap by combining silica’s extraordinary damage resistance with the advanced phase and polarization control offered by metasurfaces. By leveraging anisotropic etching techniques, we fabricate nanopillars exceeding 3 µm in height with aspect ratios up to 14. This nanofabrication leap enables precise manipulation of complex light fields at intensities far beyond the thresholds of conventional metasurfaces. We showcase their functionality in generating vortex beams with full-phase control and achieving polarization manipulation with large phase retardance at challenging long-visible wavelengths. These silica meta-optics unlock structured laser–matter interactions in extreme regimes: by scaling to centimeter-size devices that shape femtosecond pulses at the joule level, the resulting focused structured beams are expected to attain intensities far above plasma ionization thresholds. This will enable applications, such as relativistic particle acceleration and high-harmonic generation with structured light, for both tabletop ultrafast systems and large-scale laser facilities.