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 a method 100 and an apparatus 300 for cutting or ablating a particular material of the workpiece with a pulsed laser beam coupled into a fluid jet. The method comprises producing the pulsed laser beam with at least one laser source, providing the pressurized fluid jet onto the workpiece, and coupling the pulsed laser beam into the fluid jet towards the workpiece. The pulsed laser beam comprises at least two superimposed pulsations selected based on the particular material of the workpiece. A first pulsation has a different power and frequency than a second pulsation.

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.