Arrangement for the generation of a pulsed laser beam of high average output

Abstract

The invention is directed to an arrangement for generating a pulsed laser beam with high average output, in particular for generating a hot plasma which emits extreme ultraviolet (EUV) radiation. It is the object of the invention to find a novel possibility for generating a laser beam with a high repetition rate and average output which allows the repetition frequency and, therefore, the output of the laser system to be increased by connecting together a plurality of individual lasers having limited repetition rate without degradation of the beam quality on the target compared to that of an individual laser. This object is met, according to the invention, in that an oriented mirror surface is associated with each individual laser in such a way that a beam bundle which is emitted by each individual laser so as to be offset with respect to time and which is reflected at the mirror surface is coupled into a common beam path, and laser pulses in the common beam path are directed to a target one after the other in a regular, defined pulse sequence, and, with a continuously dynamic mirror movement for coupling the laser pulses into the common beam path, optical means are provided in the common beam path for compensating the directional change caused by the mirror movement.