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 $0.5\mu \text{rad}$ is achieved long term in a laboratory environment for a beam with an initially daily deviation of more than $40\mu \text{rad}$. 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 $8\text{\hspace{0.17em} fs \hspace{0.17em}pulse}$ duration for more than $10\text{\hspace{0.17em} h}$ operation time.