LASER SYSTEM AND METHOD FOR GENERATING SECONDARY RADIATION THROUGH INTERACTION OF A PRIMARY LASER BEAM WITH A TARGET MATERIAL

摘要

The invention relates to a laser system for generating secondary radiation (108) through interaction of a focused primary laser beam (104) with a target material (106), comprising a laser beam source (102) for providing a raw laser beam (110) which has ultra-short laser pulses, a target region (114) for arranging the target material (106), a beam guidance device (112) for forming the focused primary laser beam (104) from the raw laser beam (110), wherein the focused primary laser beam (104) is directed to the one target region (114) in order to interact with a target material (106) arranged in the target region (114), wherein the beam guidance device (112) has a beam focusing device (126) which is configured to form the primary laser beam (104) by focusing a laser beam (129) entering the beam focusing device (126), wherein the laser beam (129) entering the beam focusing device (126) is based on the raw laser beam (110) or corresponds to the raw laser beam (110) and wherein the beam focusing device (126) has at least two spherical mirror elements (154, 156; 176, 180) spaced apart from one another. According to the invention, the beam focusing device has a numerical aperture of between 0.001 and 0.01 as long as the primary laser beam (104) propagates in a medium with a refractive index of less than 1.01.