Abstract: The invention relates to methods for removing dirt deposits on at least one geometric structure of at least one body, said geometric structure being produced by means of microtechnology and/or nanotechnology, wherein the dirt deposits are dirt deposits resulting from an ablation or evaporation of material during creation of the geometric structure; and uses of an ultra-short pulsed laser with pulses in burst mode. The methods for removing dirt deposits and the uses of an ultra-short pulsed laser with pulses in the burst mode are characterized more particularly in that the resulting dirt deposits are easy to remove. Ultra-short pulsed laser irradiation is applied from a laser onto the geometric structure with pulses in the burst mode to remove the dirt deposits.

Abstract: A method for structuring a steel embossing roller surface includes using a short pulse laser including at least one of a femtosecond laser and a picosecond laser. The structuring is macrostructuring with dimensions of over 20 ?m and depths up to 150 ?m and more. The short pulse laser has: in single pulse operation, a fluence in the range of 0.5 J/cm2 to 3.5 J/cm2, and in burst operation, a mean burst fluence of 0.5 J/cm2 to 70 J/cm2 per pulse; a wavelength of 532 nm to 1064 nm; a repetition rate of 1 kHz to 10 MHz; a pulse to pulse spacing on the roller of 10% to 50% of the beam diameter for the femtosecond laser and of 10-25% and 40-50% of the beam width for the picosecond laser; a laser pulse position near the roller surface; and deflection velocities of up to 100 m/s and more.

Abstract: The method for structuring the surface of a steel embossing roller by means of short pulse laser, where the structuring is a macrostructuring with dimensions of over 20 ?m and depths up to 150 ?m and more, distinguishes itself by the following parameter combination: a) in single pulse operation a fluence in the range of 0.5 J/cm2 to 3.5 J/cm2 and in burst operation a mean burst fluence of 0.5 J/cm2 to 70 J/cm2 per pulse, b) wavelength of 532 nm to 1064 nm, c) repetition rate of 1 kHz to 10 MHz, d) pulse to pulse spacing on the workpiece of 10% to 50% of the beam diameter for the femtosecond laser and of 10-25% and 40-50% of the beam width for the picosecond laser, e) laser pulse position near the workpiece surface, and f) deflection velocities of up to 100 m/s and more. ***Such a method allow manufacturing a complete embossing roller with teeth and gaps for producing logos, the teeth having variable heights, shapes, and spacings, for embossing e.g. innerliners for cigarette packaging.