Abstract: A device for holding an essentially cylindrical work piece (22), in particular a jewelry ring, for machining with a laser beam (L) has at least one chuck (20) that is supported so that it is able to rotate around a rotation axis (18) and that is provided for centrally holding the work piece (22) by means of first clamping elements (30), which automatically fix the work piece (22) in position through the exertion of a spring force.

Abstract: A method for singulating a group of semiconductor packages containing a plastic molded body. The singulation of the semiconductor packages is effected along a predetermined separation area, wherein, in the predetermined separation area, a metallic layer extending over at least a partial section of the predetermined separation area has to be cut through in addition to a plastic layer formed of a material of the molded body. The method includes the steps of: making a groove into the predetermined separation area of the semiconductor packages by laser engraving, wherein at least a part of the metallic layer extending in the predetermined singulation area is removed, and subsequent separation of the semiconductor packages by mechanical sawing cut along the predetermined separation area.

Abstract: A laser-active optical fiber for a fiber laser or an optical fiber amplifier contains a laser-active fiber core (2) comprising an undoped inner region (22) which is surrounded by an outer region (24) that is doped with a laser-active material. In this manner a high-power laser beam may be generated which has a mode structure, present in the form of a ring mode, which in particular is suitable for laser machining.