Engraving Depth‐Controlled Nanohole Arrays on Fused Silica by Direct Short‐Pulse Laser Ablation

Periodic nanohole arrangements constitute an important building block of advanced photonic devices. Aside from standard nanofabrication tools, a direct laser-based approach is introduced here, that enables single-step and point-by-point machining arrays holes with subwavelength diameters depths reaching several micrometers at the surface fused silica. The method relies on simple optical arrangement including axicon combined amplitude mask to shape laser intensity in appropriately truncated micro-Bessel beams adjustable length. suitability limitations technique are investigated fabricate cylindrical nanoholes tunable depths. In particular, challenge avoiding crosstalk effects during laser-writing process high-density explored. achievability square silica, down 200 nm variable 3 20 µm spatial density defined by pitch 1.5 demonstrated. performance level shows potential direct-laser-processing towards realization integrated devices, offering highly flexible cost-effective alternative current methods.