Patent ID: 7471708

Claim:
A line narrowed gas discharge laser system adapted to fine tune a spectral quality of a laser output light pulse beam comprising: an oscillator cavity; a laser chamber within the oscillator cavity comprising a chamber housing containing a lasing medium gas; at least one peaking capacitor one terminal of which is electrically connected to the chamber housing and to a first one of a pair of gas discharge electrodes; a second one of the pair of gas discharge electrodes connected to an opposite terminal of the at least one peaking capacitor and insulated from the chamber housing; a current return path by which the at least one peaking capacitor is electrically connected to the chamber housing; the one terminal of the at least one peaking capacitor, the first one of the pair of gas discharge electrodes, the lasing medium gas, the second one of the pair of gas discharge electrodes, the current return path and the second terminal of the at least one peaking capacitor forming a head current inductive loop having an inductance value unique to the particular head current inductive loop for a given laser system; a spectral quality timing mechanism comprising a mechanism for changing the particular head current inductive loop inductance value for the particular head current inductance loop, wherein the spectral tuning mechanism further comprises an active control system to adjust the particular head current inductive loop inductance based upon feedback control of a controller having as an input an output of a spectral quality measuring system.