Abstract: A pulse stretcher includes a beam splitter configured to split an input light beam into first and second beams, a con-focal resonator including first and second con-focal mirrors, and a fold mirror. The beam splitter, con-focal resonator, and fold mirror are optically arranged such that at least a portion of the first beam is recombined with the second beam into a modified beam after an optical delay of the first beam caused by the optical arrangement. The apparatus further includes one or more optical elements in an optical path of the input light beam prior to the beam splitter such that a focal point of the first beam is formed at a distance away from the fold mirror preventing energy density-related damage to the fold mirror. The apparatus can further include one or more additional optical elements to provide re-conditioning of the modified beam. A related method is also disclosed.

Abstract: A pulse stretcher includes a beam splitter configured to split an input light beam into first and second beams, a con-focal resonator including first and second con-focal mirrors, and a fold mirror. The beam splitter, con-focal resonator, and fold mirror are optically arranged such that at least a portion of the first beam is recombined with the second beam into a modified beam after an optical delay of the first beam caused by the optical arrangement. The apparatus further includes one or more optical elements in an optical path of the input light beam prior to the beam splitter such that a focal point of the first beam is foamed at a distance away from the fold mirror preventing energy density-related damage to the fold mirror. The apparatus can further include one or more additional optical elements to provide re-conditioning of the modified beam. A related method is also disclosed.