Drive laser for EUV light source

摘要

A laser light source is disclosed having a laser oscillator producing an output beam; a first amplifier amplifying the output beam to produce a first amplified beam, and a second amplifier amplifying the first amplified beam to produce a second amplified beam. For the source, the first amplifier may have a gain medium characterized by a saturation energy (E_{s, 1}) and a small signal gain (g_{o, 1}); and the second amplifier may have a gain medium characterized by a saturation energy (E_{s, 2}) and a small signal gain (g_{o, 2}), with (g_{o, 1})>(g_{o, 2}) and (E_{s, 2})>(E_{s, 1}). In another aspect, a laser oscillator of a laser light source may be a cavity dumped laser oscillator, e.g. a mode-locked laser oscillator, q-switched laser oscillator and may further comprising a temporal pulse stretcher.