Abstract: A device for the laser welding of a tube (14) along its inner circumference with a probe (1) that can be inserted in the tube (14) has within the probe (1) devices (73-76) with which a part of a stream of shield gas flowing within the interior of the probe is divided off before it reaches an outlet opening (45) for a focused and deflected laser beam (59) and is conducted to the outer surface of the probe (1) with an axial flow component directed toward the outlet opening (45). By this means, any precipitation of welding material in the vicinity of the outlet opening (45) and in the interior of the probe (1) is reduced.

Abstract: A process and device for the laser welding of a tube (14) along its inner circumference with a probe (1) that can be inserted in the tube (14) has for the focusing and deflection of a laser beam (57) propagated within the probe (1), mainly along its longitudinal axis (10), at least one optical element (41, 65), which generates a deflected laser beam (59) focused on a focal point (F) lying outside the probe (1), the direction of whose propagation is oriented obliquely relative to the longitudinal axis (10). By this means, both the thermal stress on the deflecting elements (41, 65) mounted within the probe (1) and any precipitation of welding material in the interior of the probe (1) are reduced.