Abstract: A machining head for the laser machining of a workpiece. The machining head may include a first interface for a machining laser source for emitting a machining laser beam, a second interface for an illumination light source for emitting an illumination light beam, an exit opening for the machining laser beam and the illumination light beam, a third interface for a detector device for detecting the illumination light beam reflected from the workpiece, and guide optics for at least partial coaxial guiding of the emitted illumination light beam through the exit opening and of the illumination light beam reflected from the workpiece, through the exit opening, to the third interface. The guide optics have a polarising beam splitter for guiding at least part of the emitted illumination light beam in the direction of the exit opening, and a retardation plate between the polarising beam splitter and the exit opening.

Abstract: The invention relates to a machining head (100) for the laser machining of a workpiece, having a first interface (102) for a machining laser source for emitting a machining laser beam; a second interface (104) for an illumination light source for emitting a linearly polarised illumination light beam; an exit opening (112) for the machining laser beam and the illumination light beam; a third interface (106) for a detector device for detecting the illumination light beam reflected from the workpiece; and guide optics (116, 117) for at least partial coaxial guiding of the emitted illumination light beam through the exit opening and of the illumination light beam reflected from the workpiece, through the exit opening, to the third interface. The guide optics have a polarising beam splitter (116) for guiding at least part of the emitted linearly polarised illumination light beam in the direction of the exit opening; and a retardation plate (117) disposed between the polarising beam splitter and the exit opening.