Abstract: A ribbon laser has a laser gas present between elongated electrodes, whose flat surfaces lie in pairs opposite one another. The laser contains a large number of electrode pairs and a respective narrow discharge chamber is formed between each of the pairs. The discharge chambers are optically intercoupled by folding reflectors and are positioned adjacent to one another in such a way that the central planes of the discharge chambers, running parallel to the flat surfaces of the electrodes, lie on a common plane. At least one waveguide is provided to guide the laser beam between the respective adjacent discharge chambers that are directly intercoupled.

Abstract: A mirror for a laser beam, in which at least one first cooling channel for a cooling fluid is disposed for cooling a zone that is thermally impinged by a laser beam. The cooling channel extends in the interior of the mirror such that the zone is cooled at least substantially symmetrically to its center and that the cooling fluid heated up in this zone is directed to thermally unaffected zones of the mirror to compensate for thermally caused stresses.

Abstract: The laser welding device for welding hollow sections (1) and flat sections which are to be welded flush to one another, having a detection device (7) for one or both edges to be welded and having a tracking device (7, 8) for the welding head which is adjustable transversely to the direction of the weld seam, is characterized in that it exhibits deflecting mirrors (10, 11) for the laser light which are disposed obliquely in relation to the laser beam axis (9) and which are pivotable about this axis (9), in that the detection device is designed as a mechanical scanner (7), and in that the scanner (7) and the deflecting mirrors (10, 11) are connected to one another for common pivoting movement (FIG. 1).

Abstract: The laser welding apparatus has a nozzle (10) for generating a transversely extending gas current (14) between the optical system (4, 5, 6) and the beam focus for the deflection of particles moving in a direction towards the optical system (4, 5, 6). In order to reduce the level of noise development and to improve the protective action of the gas current curtain (14), the receiving aperture (12) of a gas exhaust line (13) is disposed opposite the nozzle (10), and furthermore the nozzle (10) is provided within an injector envelope (11), which forms together with the gas exhaust line (13) a substantially continuous flow channel.