VERY HIGH REPETITION RATE NARROW BAND GAS DISCHARGE LASER SYSTEM

A laser system and method is disclosed which may comprise a first line narrowed gas discharge laser system producing a first laser output light pulse beam at a pulse repetition rate of >=2000 Hz; a second line narrowed gas discharge laser system producing a second laser output light pulse beam at a pulse repetition rate of >=2000 Hz; a beam combiner combining the first and second output light pulse beams into a combined laser output light pulse beam with a >=4000 Hz pulse repetition rate. The apparatus and method may comprise a compression head comprising a storage device being charged at x times per second; a gas discharge chamber comprising at least two sets of paired gas discharge electrodes; at least two magnetically saturable switches, respectively connected between the compression head charge storage device and one of the at least two sets of paired electrodes.