Patent ID: 8092446

Claim:
A device for material processing by laser radiation, said device comprising: a source of laser radiation emitting pulsed laser radiation for interaction with the material; optics focusing the pulsed laser radiation to a center of interaction in the material; a scanning unit shifting positions of the center of interaction within the material, wherein each laser pulse interacts with the material in a zone surrounding the center of interaction assigned to said laser pulse so that material is separated in the zones of interaction; and a control unit that is configured to control the scanning unit and the source of laser radiation such that a cut surface is produced in the material by sequential arrangement of zones of interaction, wherein the control unit controls the source of laser radiation and the scanning unit such that the cut surface includes a first cut surface part and second cut surface part wherein the second cut surface part surrounds the first cut surface part and wherein the control unit sets a parameter influencing coarseness of the cut surface by controlling the scanning unit and the source of laser radiation such that the second cut surface part is coarser than the first cut surface part.