Unstable laser resonator for generating a stable fundamental mode beam profile

摘要

The reflecting surfaces within the resonator are minimized in an unstable laser resonator having a radially-dependent output end reflection profile and a passive Q-switch so that the least possible competing resonator geometries can be formed. For this purpose, a saturable absorber foil can be provided as a passive Q-switch element mounted so as to be inclined with respect to the optical axis. Furthermore, it is advantageous to use an output reflector having highly precise parallel boundary surfaces and to align this output reflector with high precision parallel to the end surfaces which delimit the laser medium.