Gas discharge laser with pulse multiplier

A gas discharge laser system with pulse multiplication comprising:

• A) a gas discharge laser configured to produce a laser output pulse beam at a pulse repetition rate of at least 2000 laser output pulses per second, each pulse defining intensity values:
• B) a pulse multiplier optical system arranged to receive said output pulse laser beam and to multiply the number of pulses per second by at least a factor of two so as to produce a single multiplier output pulse beam comprised of a larger number of pulses with substantially reduced intensity values as compared with the laser output pulses, and pulse multiplier optical system comprising:
• (1) a first beam splitter arranged to separate a portion of said output beam, the separated portion defining a delayed portion, and the output beam defining a beam size and angular spread at said first beam splitter;
• (2) a first delay path originating and terminating at said first beam splitter said first delay path comprising at least two focusing mirrors, said mirrors being arranged to focus said delayed portion at a focal point within said first delay path and to return said delayed portion to said first beam splitter with a beam size and angular spread equal to or approximately equal to the beam size and angular spread of the output beam at said first beam splitter.