Abstract: A high-power flowing-gas laser comprises an outer housing, an optical system including a laser channel within the housing, an impeller driven by a motor for producing a flow of gas through the laser channel, and an independent mounting for mounting the optical system to the support idependently of the housing mounting such as to isolate the optical system from the vibrational disturbances of the impeller and its motor drive. The laser channel is folded so as to be constituted of a plurality of laser channel legs disposed in a polygon configuration, there being a gas flow channel for each laser channel leg and a conduit arrangement directing the gas to flow transversely across the legs radially inwardly from the outer region of the polygon to a common collection region within the polygon.

Abstract: Apparatus for establishing and maintaining a stable discharge across a stream of flowing gas, particularly useful for high-power lasers, comprises working electrodes disposed on opposite sides of the gas flow channel, and starting electrodes adjacent to the upstream working electrodes. Each working electrode includes a ballast impedance and is connected between a high-voltage source and a point of fixed reference potential. Each starting electrode includes a substantially larger ballast impedance and is connected to the point of fixed reference potential such that each starting electrode is effective to bring the point of fixed reference potential to the upstream working electrode to start the discharge, and to draw little current after the discharge has been started.

Abstract: A high-power flowing-gas laser comprises an outer housing, an optical system including a laser channel within the housing, and an impeller for producing a flow of gas through the laser channel. The laser channel is folded so as to be constituted of a plurality of legs disposed in a polygon, preferably square, configuration, there being a gas flow channel for each laser channel leg and including an axially-extending inlet section and a radially-extending outlet section, the latter being formed with aligned laser openings for accommodating the laser beam of the respective laser channel leg. The laser further includes an internal partition wall between the outlet end of the impeller and the inlet ends of the gas flow channels for confining the gas flow from the impeller to the inlet ends of the gas flow channels, which partition substantially precludes gas flow into the gas flow channel legs through the aligned laser openings at the outlet sections of the gas flow channels.

Abstract: A cooled mirror particularly useful in lasers conducts a cooling fluid through a plurality of parallel paths to impinge on the underface of the reflector member at a plurality of discrete points thereon. The velocity of the cooling fluid is increased such that it issues in the form of a high-velocity jet at each of the discrete impingement points on the underface of the reflector member. The reflector member is thin and flexible and is supported from a rigid base by a plurality of spaced supporting elements in such manner so as to reduce bending of the reflector member by thermal deformation.

Abstract: Apparatus for establishing and maintaining a stable electrical discharge across a stream of gas flowing through a gas flow channel, particularly useful in high-power lasers, comprises a plurality of modular elements each including a plurality of electrodes, a ballast impedance for each electrode, and a cooling element for each electrode in thermal communication with the electrode and its ballast impedance, all embedded within a block of insulating material. The ballast impedances for the electrodes at the downstream side of the gas flow channel have lower impedance values than those for the electrodes at the upstream side of the channel so as to compensate for the lower impedance of the gas flowing through the channel at the downstream side and to produce a substantially constant voltage across the various portions of the channels.

Abstract: A high-power flowing-gas laser comprises a laser channel folded to include at least two legs angularly disposed to each other in a common plane and having a single folding mirror between them such that the laser rays through one leg, on the upstream side thereof with respect to the gas flowing transversely across that leg, are reflected by the folding mirror so as to be transposed to the downstream side of the other leg with respect to the gas flowing transversely across the other leg. A number of embodiments are described wherein the laser channel is folded to include four or other even number of legs according to a polygonal configuration, there being a separate flowing gas channel for each leg, all the gas channels directing the gas flow radially inwardly to a common collection region. Among the advantages provided by the described constructions are compensation for phase distortion and amplitude variations, and maximum laser channel length and laser output for a given system size and volume.