Abstract: A laser machining apparatus includes a nozzle connected to a pressurized gas and liquid reservoir for propelling a fine spray, mist or stream of a liquid such as water at the workpiece to be machined. A laser beam, preferably as may be generated by a UV laser or other source of exposure radiation, but is not strongly absorbed by the liquid assist material, is focused to the workpiece using, e.g., a focusing or imaging lens, while the fine spray, mist or liquid stream is propelled at the workpiece creating a layer of the liquid on its surface as the beam is incident upon the workpiece for machining.

Abstract: An F.sub.2 -laser has a discharge chamber containing a laser gas mixture including fluorine as a laser active component and neon as a buffer gas. The gas mixture is surrounded by a resonator and supplied with a pulsed discharge by a pair of electrodes connected to a power supply circuit. The concentration of neon within the gas mixture is preferably higher than any other constituent gas, and is more preferably the only gas accompanying the laser active molecular fluorine. In addition, the gas mixture is preferably maintained at an elevated temperature such as near, yet below, a temperature at which outgassing occurs within the discharge chamber.