a laser system for the generation of an ultra - short light pulse — with a laser resonator which contains at least one active solid - state oscillator element , preferably a thin disk of a laser - active crystal with a high amplification bandwidth , particularly of a “ quasi - three - level ” system such as yb : yag — comprises at least one respective arrangement for phasecoupling of the laser modes and for dispersion compensation . for industrial applications , in order to be able to emit ultra - short pulses with very high average powers in a power - scalable fashion while being constructed optimally simply and inexpensively , the arrangement for phase coupling is constructed as a passive , non - linear element , and a prismless arrangement for dispersion compensation is provided .