A method for producing a cavity in a substrate composed of hard brittle material is provided. A laser beam of an ultrashort pulse laser is directed a side surface of the substrate and is concentrated by a focusing optical unit to form an elongated focus in the substrate. Incident energy of the laser beam produces a filament-shaped flaw in a volume of the substrate. The filament-shaped flaw extends into the volume to a predetermined depth and does not pass through the substrate. To produce the filament-shaped flaw, the ultrashort pulse laser radiates in a pulse or a pulse packet having at least two successive laser pulses. After at least two filament-shaped flaws are introduced, the substrate is exposed to an etching medium which removes material of the substrate and widens the at least two filament-shaped flaws to form filaments. At least two filaments are connected to form a cavity.

An irradiation device for additively manufacturing three-dimensional objects may include a beam generation device configured to generate an energy beam, an optical modulator including a micromirror array disposed downstream from the beam generation device, and a focusing lens assembly disposed downstream from the optical modulator. The micromirror array may include a plurality of micromirror elements configured to reflect a corresponding plurality of beam segment of the energy beam along a beam path incident upon the focusing lens assembly. The focusing lens assembly may include one or more lenses configured to focus the plurality of beam segments such that for respective ones of a plurality of modulation groups including a subset of micromirror elements, a corresponding subset of beam segments are focused to at least partially overlap with one another at a combination zone corresponding to the respective modulation group.

The illumination optical system includes a beam shaper which converts an intensity distribution of a laser beam in each of a short axis direction and a long axis direction, which is a Gaussian distribution, into an intensity distribution of a parallel beam on a modulation surface of the optical modulator in each of the short axis direction and the long axis direction, which is a top hat distribution. The modulation surface and an irradiated surface are optically conjugated with respect to the long axis direction by a third lens and a fourth lens. Further, the modulation surface and a front focus position of the fourth lens are optically conjugated with respect to the short axis direction by a first lens, a second lens, and the third lens. The fourth lens condenses a beam having a top hat distribution at the front focus position onto the irradiated surface.

In a laser processing apparatus for refining magnetic domains of a grain-oriented electromagnetic steel sheet by setting a laser beam to be focused on the grain-oriented electromagnetic steel sheet and scanned in a scanning direction, the laser beam focused on the grain-oriented electromagnetic steel sheet is linearly polarized light, and an angle between a linear polarization direction and the scanning direction is higher than 45° and equal to or lower than 90°.

A peeling method at low cost with high mass productivity is provided. A silicon layer having a function of releasing hydrogen by irradiation with light is formed over a formation substrate, a first layer is formed using a photosensitive material over the silicon layer, an opening is formed in a portion of the first layer that overlaps with the silicon layer by a photolithography method and the first layer is heated to form a resin layer having an opening, a transistor including an oxide semiconductor in a channel formation region is formed over the resin layer, a conductive layer is formed to overlap with the opening of the resin layer and the silicon layer, the silicon layer is irradiated with light using a laser, and the transistor and the formation substrate are separated from each other.

An optical device, its use, and a method for interference structuring of a sample. A laser emits a laser beam that is split into at least two partial beams by a beam splitter. A first cylindrical lens and a second cylindrical lens for refracting the partial beams into an interference area are arranged in the beam path. The partial beams interfere in such a way that a structure having linear structure elements may be formed in a structural region of the sample. The cylinder axis of the first cylindrical lens is aligned parallel to the cylinder axis of the second cylindrical lens.

Methods and apparatuses for additive manufacturing are described. A method for additive manufacturing may include exposing a layer of material on a build surface to one or more projections of laser energy including at least one line laser having a substantially linear shape. The intensity of the line laser may be modulated so as to cause fusion of the layer of material according to a desired pattern as the one or more projections of laser energy are scanned across the build surface.

An irradiation device for additively manufacturing three-dimensional objects may include a beam generation device configured to generate an energy beam, an optical modulator including a micromirror array disposed downstream from the beam generation device, and a focusing lens assembly disposed downstream from the optical modulator. The micromirror array may include a plurality of micromirror elements configured to reflect a corresponding plurality of beam segment of the energy beam along a beam path incident upon the focusing lens assembly. The focusing lens assembly may include one or more lenses configured to focus the plurality of beam segments such that for respective ones of a plurality of modulation groups including a subset of micromirror elements, a corresponding subset of beam segments are focused to at least partially overlap with one another at a combination zone corresponding to the respective modulation group.

A method of fiber laser processing of thin film deposited on a substrate includes providing a laser beam from at least one fiber laser which is guided through a beam-shaping unit onto the thin film. The beam-shaping optics is configured to shape the laser beam into a line beam which irradiates a first irradiated thin film area Ab on a surface of the thin film, with the irradiated thin film area Ab being a fraction of the thin film area Af. By continuously displacing the beam shaping optics and the film relative to one another in a first direction at a distance dy between sequential irradiations, a sequence of uniform irradiated thin film areas Ab are formed on the film surface defining thus a first elongated column. Thereafter the beam shaped optics and film are displaced relative to one another at a distance dx in a second direction transverse to the first direction with the distance dx being smaller than a length of the irradiated film area Ab. With the steps performed to form respective columns, the elongated columns overlap one another covering the desired thin film area Af. The dx and dy distances are so selected that that each location of the film area Af is exposed to the shaped laser beam during a cumulative predetermined duration.

A method for processing a transparent workpiece includes forming a contour of defect in the transparent workpiece and separating the transparent workpiece along the contour using an infrared laser beam. During separation, the method also includes detecting a position and propagation direction of a crack tip relative to a reference location and propagation direction of an infrared beam spot, determining a detected distance and angular offset between the crack tip and the reference location of the infrared beam spot, comparing the detected distance to a preset distance, comparing the detected angular offset to a preset angular offset, and modifying at least one of a power of the infrared laser beam or a speed of relative translation between the infrared laser beam and the transparent workpiece in response to a difference between the detected distance and the preset distance and between the detected angular offset and the preset angular offset.