Spatial control of femtosecond laser system output with submicroradian accuracy

A system for the course control and spatial stabilization of the output beam of a femtosecond laser system is realized. An accuracy of 0.5 microrad is achieved long term in a laboratory environment for a beam with an initially daily deviation of more than 40 microrad. The application and importance of the method is illustrated for laser pulse shortening in a hollow waveguide resulting in a stable output power and an 8 fs pulse duration for more than 10 h operation time.