Abstract: An apparatus and a method for producing nanostructured surfaces are particularly suited for producing surfaces having very low roughness over large lateral extents. The method includes the following steps: providing an article having a surface to be structured; generating short-pulse laser radiation with laser pulses whose pulse durations lie in the subnanosecond range, preferably in the range of 100 fs to 300 fs, directing the short-pulse laser radiation onto the surface to be structured on the article, such that a fluence F of each individual pulse of the short-pulse laser radiation is less than a multishot threshold fluence Fth for a multishot laser ablation, but the fluence F is chosen to be high enough that defects can be produced by way of nonlinear interactions. Preferably, a fluence F in the range of 65% to 95% of the multishot threshold fluence Fth for a multishot laser ablation is used.

Abstract: The invention relates to a method for finely polishing/structuring thermosensitive dielectric materials, in particular materials exhibiting a low thermal expansion coefficient, by a laser beam consisting in directing an intensive ultrashort laser beam to a processable material surface, in adjusting the action time within a range from 10-13 s to 10-11 s and a laser pulse energy in such a way that it is less than an ablation threshold but sufficient for provoking a Coulomb explosion. The inventive method makes it possible to carry out a material removal within a nanometer range by means of laser ultrashort pulses ranging between picoseconds and subpicoseconds, wherein the material surface is finely polished during a pre-ablation process step (removal less than the ablation range) and the processable surface is low-heated (approximately up to 10° C., only) due to the extremely shot laser beam action time.