Patent ID: 8780947

Claim:
A mirror arrangement for guiding a laser beam in a laser system, in particular a laser system for generating femtosecond pulses or picosecond pulses, having at least one first end mirror, and one second end mirror with a concave surface, in which the first and the second end mirrors form a resonator having an optical resonator axis connecting the end mirrors, the laser beam is guided as input laser beam into the resonator, and is guided out of the resonator again after multiple reflection at, respectively, the first and the second end mirrors as output laser beam, and the sequence of the reflections at the first and the second end mirrors fixes a direction of rotation, defined as axis of rotation relative to the resonator axis, between the first and second end mirrors in the resonator, a first beam path being defined thereby, wherein the resonator is designed such that the direction of rotation is reversed at a reversing point by retroreflection with an angular change so that an identical or similar second beam path is at least partially passed through, said second beam path is offset or twisted with its reflection points on the end mirrors relative to the first beam path and the laser beam passes through the resonator at least partially in a direction of rotation opposite to the first beam path.