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 adaptively splitting a coherent primary light beam, comprising producing a desired far-field distribution by phase modulating the primary light beam with a Spatial Light Modulator (SLM), the primary coherent light beam being directed to reflect on a display element of the spatial light modulator, thereby avoiding any moving elements to shape the primary coherent light beam, extracting from the primary light beam, after it has passed the spatial light modulator, a monitoring beam and a main beam, measuring the monitoring beam with a camera, directing the desired far-field distribution in the monitoring beam on a sensor surface of the camera.

Abstract: The present application relates to a device for the mask projection of femtosecond or picosecond laser beams (2) onto a substrate surface, in which the laser beam (2) consisting of laser beam pulses is, at a location of the optical axis, formed to make laser beam pulses with an expanded laser beam cross section or laser beam pulses with a reduced laser beam cross section and said laser beam (2) has a homogeneous intensity distribution over the laser beam cross section. A stop (6) with a predetermined stop aperture geometry and a mask (7) with a predetermined mask aperture geometry are positioned in succession in the beam (2) path at the location.

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: In the method for structuring at least one area of a solid body surface provided with a ta-C coating, by means of a first laser, preferably an excimer laser having pulse durations in the nanosecond range, a first structure is produced upon which a second, ripple-like structure is superposed by means of a second laser, preferably having pulse durations in the femtosecond range. Preferentially, the excimer laser structuring is carried out according to the mask projection technique and the femtosecond laser structuring according to the focus technique. This method allows the rational manufacture of very complex, extremely fraud-resistant authentication features and/or of esthetically attractive, optical diffraction effective colored patterns.

Abstract: In the method for producing masks and/or diaphragms for a laser installation for the creation of microstructures on a solid body surface according to the mask projection technique, predetermined opaque surface portions which scatter the laser radiation are produced in the mask and/or diaphragm substrate by roughening and modifying the latter by means of a femtosecond, picosecond or fluor laser beam. Such masks and diaphragms have a strongly improved lifetime and accuracy and may e.g. serve for the creation of blazed gratings which, arranged in diffraction grating arrays on a solid body surface, serve for producing spectral colors and mixed colors of high brilliance.

Abstract: The present application relates to a device for the mask projection of femtosecond or picosecond laser beams (2) onto a substrate surface, in which the laser beam (2) consisting of laser beam pulses is, at a location of the optical axis, formed to make laser beam pulses with an expanded laser beam cross section or laser beam pulses with a reduced laser beam cross section and said laser beam (2) has a homogeneous intensity distribution over the laser beam cross section. A stop (6) with a predetermined stop aperture geometry and a mask (7) with a predetermined mask aperture geometry are positioned in succession in the beam (2) path at the location.

Abstract: A packing foil having optical diffraction effective areas and/or authentication features includes at least a first structure produced by passing a homogeneous intensity distribution spot of a laser beam having laser pulse durations in a nano-second range through a mask and a diaphragm before imaging the laser beam on at least one area of an exposed surface of the packaging foil using imaging optics positioned downstream of the mask and the diaphragm, and at least a second structure superposed on the first structure, the second structure produced by a second laser having pulse durations in the pico- or femtosecond range.

Abstract: In the method for structuring at least one area of a solid body surface provided with a ta-C coating, a mask in the homogenous spot of the optical system is used in order to shape the beam in the mask projection technique and then a diaphragm in front of the imaging optics. A structure is applied by means of an excimer laser having pulse durations in the nanosecond range, a number of mask and diaphragm combinations being arranged in a exchanger device and the exchanger device being adapted to place both one of the masks and one of the diaphragms in the beam path of the laser independently of each other, the masks and diaphragms being arranged in holders while being displaceable linearly or rotatively and rotatable about themselves. This method allows the rational manufacture of very complex, extremely fraud-resistant authentication features and/or of esthetically attractive, optical diffraction effective colored patterns.

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.

Abstract: In the method for producing masks and/or diaphragms for a laser installation for the creation of microstructures on a solid body surface according to the mask projection technique, predetermined opaque surface portions which scatter the laser radiation are produced in the mask and/or diaphragm substrate by roughening and modifying the latter by means of a femtosecond, picosecond or fluor laser beam. Such masks and diaphragms have a strongly improved lifetime and accuracy and may e.g. serve for the creation of blazed gratings which, arranged in diffraction grating arrays on a solid body surface, serve for producing spectral colors and mixed colors of high brilliance.

Abstract: In the method for structuring at least one area of a solid body surface provided with a ta-C coating, by means of a first laser, preferably an excimer laser having pulse durations in the nanosecond range, a first structure is produced upon which a second, ripple-like structure is superposed by means of a second laser, preferably having pulse durations in the femtosecond range. Preferentially, the excimer laser structuring is carried out according to the mask projection technique and the femtosecond laser structuring according to the focus technique. This method allows the rational manufacture of very complex, extremely fraud-resistant authentication features and/or of esthetically attractive, optical diffraction effective colored patterns.

Abstract: In the method for structuring at least one area of a solid body surface provided with a ta-C coating, a mask in the homogenous spot of the optical system is used in order to shape the beam in the mask projection technique and then a diaphragm in front of the imaging optics. A structure is applied by means of an excimer laser having pulse durations in the nanosecond range, a number of mask and diaphragm combinations being arranged in a exchanger device and the exchanger device being adapted to place both one of the masks and one of the diaphragms in the beam path of the laser independently of each other, the masks and diaphragms being arranged in holders while being displaceable linearly or rotatively and rotatable about themselves. This method allows the rational manufacture of very complex, extremely fraud-resistant authentication features and/or of esthetically attractive, optical diffraction effective colored patterns.