Abstract: In the cutting of workpieces by means of a laser beam, gas is blown onto workpiece at high speed together with the beam. It is proposed to design gas outflow nozzles (60) in such a way that they are formed as grooves in the conical end face (49) of a nozzle insert (47) and, on the other hand, are formed by a nozzle cap (48) which has a portion of such a matching conical shape that the grooves are covered. It is also proposed to provide a unifying chamber (formed by an attached cap), in which the gas jets are unified, so that they then flow out, together with the laser beam, as a single gas jet.

Abstract: The machining results of high-power lasers with machining optical systems 5) for beam shaping are dependent on the fact that decisive machining parameters, namely the beam power, the beam diameter, the position of the beam relative to the optical axis (54) and the intensity of the radiation reflected back, are supervised. To this end, the invention proposes a process by which the essential beam parameters can be measured during machining directly at a machining optical system (25) designed in an appropriate manner according to the invention. To this end, the appropriate measurement value receivers are associated, according to the invention, with the deflecting mirror (26) and/or the focusing mirror (27) of the machining optical system (25).