Patent ID: 7778302

Claim:
An apparatus comprising: a pulsed excimer or molecular fluorine gas discharge laser system comprising: a seed laser oscillator producing an output comprising a laser output light beam of pulses comprising: a first gas discharge excimer or molecular fluorine laser chamber; a laser amplification stage containing an amplifying gain medium in a second gas discharge excimer or molecular fluorine laser chamber receiving the output of the seed laser oscillator and amplifying the output of the seed laser oscillator to form a laser system output comprising a laser output light beam of pulses, comprising: a ring power amplification stage; and a coherence busting mechanism intermediate the seed laser oscillator and the ring power amplification stage comprising a beam splitter separating the seed laser output into a main beam and a beam entering an optical delay path having a delay length longer than the coherence length of a pulse in the seed laser output; wherein the coherence busting mechanism comprises a coherence busting optical structure generating multiple sub-pulses delayed sequentially from a single input pulse, wherein each sub-pulse is delayed from the following sub-pulse by more than the coherence length of the pulse light.