High-precision multi-focus laser sculpting of microstructured glass

Precision sculpting of glass with defined surface microstructures is vital due to the miniaturization and integration of glass-based devices, while it is still challenging as the high brittleness of glass. We here create a three-dimensional multi-focus laser for glass micro-sculpting through a beam-shaping technology based on the superposition of lens and grating phase diagrams. The multi-focus laser modification in tandem with chemical etching enables the fabrication of glass microstructures with highly adjustable profiles. Refractive-index-induced deviations are migrated via algorithm correction to ensure multi-focus positional accuracy. Energy un-uniformity due to equidistant laser spots arrangement is eliminated through their coordinate randomization following the target profiles. Finally, uniform laser spots with a proper point-to-point distance create connected cracks inside glass, enabling efficient etching with enhanced rates along the modified profile and the fabrication of surface microstructures. We demonstrate diverse groove arrays with profiles of trapezoid, semicircle, and triangle, revealing low roughness around 1.3 μm, a high depth-width ratio of 3:1, and depth up to 300 μm, which underscore broad applications such as fiber packaging.