The invention relates to a laser system comprising a first laser source (1) with a laser resonator (2) for generating a first pulsed laser beam (3), said laser resonator (2) having a back mirror (4), an outcoupling mirror (5) and an active lasing medium (6) in between. According to the invention the laser system further comprises a second laser source (7) for generating a second pulsed laser beam (8) and a first optical block (9), wherein the first optical block (9) comprises a coupling polarizer (10) and a first polarization rotator (11). The first optical block (9) is movable back and forth between an active position and a passive position, wherein in its active position the first optical block (9) is located between the outcoupling mirror (5) and the active lasing medium (6) such, that the coupling polarizer (10) couples the second pulsed laser beam (8) into the laser resonator (2) of the first laser source (1) while the first polarization rotator (11) is positioned between the outcoupling mirror (5) and the coupling polarizer (10). In the active position of the first optical block (9) a second polarization rotator (13) is located between the first optical block (9) and the back mirror (4).
