Patent ID: 7218661

Claim:
A very narrow band two chamber high repetition rate F 2 gas discharge laser system comprising: A) a first laser unit comprising: 1) a first discharge chamber containing; a) a first laser gas b) a first pair of elongated spaced apart electrodes defining a first discharge region, 2) a first fan producing sufficient gas movement of said first laser gas in said first discharge region to clear from said first discharge region, following each gas discharge, substantially all discharge produced ions prior to a next gas discharge when operating at a repetition rate in the range of 4,000 gas discharges per second or greater, 3) a first heat exchanger system removing heat energy from said first laser gas, B) a line selection unit minimizing energy outside of a single selected line spectrum, C) a second laser unit comprising: 1) a second discharge chamber containing: a) a second laser gas, b) a second pair of elongated spaced apart electrodes defining a second discharge region 2) a second fan for producing sufficient gas movement of said second laser gas in said second discharge region to clear from said second discharge region, following each gas discharge, substantially all discharge produced ions prior to a next gas discharge when operating at a repetition rate in the range of 4,000 gas discharges per second or greater, 3) a second heat exchanger system removing heat energy from said second laser gas, D) a pulse power system configured to provide electrical pulses to said first pair of electrodes and to said second pair of electrodes sufficient to produce laser output pulses at rates of about 4,000 laser output pulses per second with precisely controlled laser output pulse energies in excess of about 5 mJ, E) a laser beam measurement and control system for measuring the laser output pulse energy of laser output pulses produced by said two chamber laser system and controlling said laser output pulses in a feedback control arrangement, and wherein output laser beams from said first laser unit are utilized as a seed beam for seeding said second laser unit.