Abstract: The invention relates to an apparatus 100 for machining a workpiece with a laser beam 101 coupled into a fluid jet. The apparatus 100 comprises a laser unit 101a for providing the laser beam 101, a nozzle unit 102 with an aperture 102a for producing the fluid jet, and an optical unit 103 configured to provide the laser beam 101 from the laser unit 101a onto the nozzle unit 102. Further, the apparatus 100 comprises a control unit 104 configured to control 108, 110 the optical unit 103 and/or nozzle unit 102 to change a point of incidence 109 of the laser beam 101 on the nozzle unit 102. The apparatus 100 also comprises a sensing unit 105 configured to sense laser light 106 reflected from a surface 102b of the nozzle unit 102 and produce a sensing signal 107 based on the sensed reflected laser light 106.

Abstract: The invention relates to an apparatus 100, 200, 300, 700 and a method 400 for machining a workpiece 101 with a laser beam 102. The apparatus 100, 200, 300, 700 comprises a machining unit 103 configured to provide a pressurized fluid jet 104 onto the workpiece 101 and to couple the laser beam 102 through at least one optical element 105 into the fluid jet 104 towards the workpiece 101. Further, it comprises a sensing unit 107 arranged to receive a laser-induced electromagnetic radiation 106 propagating away from the workpiece 101 through the fluid jet 104 and through at least one optical element, and configured to convert the received radiation 106 into a signal 108. The apparatus 100, 200, 300, 700 also comprises a signal processing unit 109 configured determine a state of machining the workpiece 101 based on the signal 108.

Abstract: The invention relates to an object (1) that is cut by means of a laser and a water beam and to further processing of the cut material. The object is glued on a carrier (3) that is provided with an adhesive and can be transparent for the radiation used in the water beam (7). The carrier can be a solid body and preferably a fibrous mat (3). Said body or mat is penetrated by the water beam. The object (1) or the cut material thereof is held on the carrier (3) before, during and after cutting through in such a way that said object or material does not change position. In a preferred embodiment, a silicon wafer is used as the object because of the high cutting exactness to be obtained. Other materials can also be used.