Millimeter long PMMA nanofibers—a new form of material removal in laser ablation

A new form of material removal in laser ablation is explained. Long (up to 1 mm) nanofibers with a radius approximately 150–200 nm are obtained when a polymethylmethacrylate (PMMA) target is irradiated with a single pulse of a KrF excimer laser. The model suggests an expulsion of energetic droplets by an intense pressure of the plume to the exterior of the spot. For the transient melt of a polymeric viscous liquid resulting from UV laser excitation, such droplets provide the heads of the jets pulled from the melt bath, giving rise, after re-solidification, to nanofibers. The initial speed of fiber spinning is extremely high (840 m/s, maximum velocity) and unusual properties of the laser-produced nanofibers may be expected.