US Patent 7778306 Laser system

The invention relates to laser system with a laser source and an articulated arm. The articulated arm has an optical arrangement for guiding a laser beam from the laser source along an optical path in the articulated arm to a target location. Within the optical path at least one crossing area (focus or focal point) of the laser beam is provided. The optical arrangement has at least one optical cell with an input window and an output window for passing the laser beam therethrough, wherein the crossing area is positioned within the optical cell. The optical cell has a gas fill with an energy threshold for ionization that is increased in comparison to that of ambient air.