Extremely high aspect ratio nanowires in single shot from femtosecond higher-order Bessel beams

Ultrafast Bessel beams are well recognized for enabling efficient processing of dielectrics thanks to their propagation-invariant focus. We show that single-shot irradiation of glass or fused silica with higher-order Bessel beams generates ultra-long nano-wires, about 200 nm in diameter and up to millimeters long, through a vapor-driven jet of molten glass. Scanning the beam produces a nanofoam-like layer of interwoven nano-wires. This simple approach opens new perspectives for fabricating complex 3D nanofoam materials for nanophotonics, electrodes, and catalytic applications.