Patent ID: 7317196

Claim:
A high conversion efficiency laser produced plasma extreme ultraviolet (“EUV”) light source utilizing a pulsed laser beam to irradiate a plasma initiation target, comprising; a laser output light pulse beam source, producing laser output light pulses at a selected pulse repetition rate and having a pulse duration due to the characteristics of the operation of the output light pulse beam source that is not short enough form obtaining a desired EUV conversion efficiency; a power amplifier laser system; a pulse duration shortener comprising: a selection mechanism selecting a first selected portion of an output light pulse produced in the output light pulse beam source and directing the first selected portion through the power amplifier while an amplifying medium is present in the power amplifier, and for selecting a second portion of the output light pulse produced in the output light pulse beam source and directing the second selected portion through the power amplifier while the amplifying medium is present in the power amplifier; a combining mechanism substantially overlapping the first and second portions to form a combined beam to irradiate the target having a pulse duration short enough for producing the desired conversion efficiency.