A laser welding device includes a laser that generates a laser beam, an
optics, and a limiting apparatus. The optics has a focal length of at
least 200 nm and being configured to focus the laser beam onto a
processing zone of a workpiece. The limiting apparatus limits a mixture
of welding gases and heated ambient air, produced during laser welding,
within the laser beam to a region that is less than the focal length from
a surface of the workpiece.