Confocal pulse stretcher

A gas discharge laser system producing a laser output pulse and a method of operating such a system is disclosed which may comprise a pulse stretcher which may comprise a laser output pulse optical delay initiating optic directing a portion of the laser output pulse along a laser system output pulse optical axis and diverting a portion of the output pulse into an optical delay having an optical delay path and which may comprise a plurality of confocal resonators in series aligned to deliver an output of the optical delay to the laser output pulse optical delay initiating optic; an optical axis alignment mechanism comprising an radial mirror positioning mechanism operable to position the output of the optical delay to the align with the portion of the laser output pulse transmitted along the optical axis of the portion of the laser system output pulse transmitted by the laser output pulse optical delay initiating optic.