Patent ID: 7369597

Claim:
A high peak power short pulse duration gas discharge laser system producing a laser output pulse comprising: a pulse stretcher comprising: a laser output pulse optical delay initiating optic diverting a portion of the output laser pulse into an optical delay having an optical delay path and comprising: a plurality of confocal resonators in series aligned to deliver the output of the optical delay to the laser output pulse optical delay initiating optic; and a first confocal resonator cell of the plurality of confocal resonators comprising: a first concave spherical mirror having a radius of curvature receiving an input beam from the laser output pulse optical delay initiating optic comprising the portion of the output laser pulse at a first point on a face of the first concave spherical mirror and generating a first reflected beam; a second concave spherical mirror having the same radius of curvature and separated from the first concave spherical mirror by the radius of curvature and receiving the first reflected beam at a first point on a face of the second concave spherical mirror and generating a second reflected beam incident on a second point on the face of the first concave spherical mirror, the second reflected beam being reflected by the first concave spherical mirror from the second point on the first mirror to form an output beam from the first confocal resonator cell; and, a second confocal resonator cell receiving the output beam of the first confocal resonator cell as an input beam of the second confocal resonator cell.