  Actively Q-switched lasers are widely used tools which are required to
produce stable output pulse energies for many applications. In this paper, a
model-based control concept for actively Q-switched lasers is presented which
stabilises their nonlinear pulse-to-pulse dynamics and rejects stochastic
disturbances arising from amplified spontaneous emission. The feasibility of
the control task is demonstrated to strongly depend on the design of the
semi-active prelasing approach. In contrast to state-of-the-art hardware-based
controllers, the proposed concept is flexible and cost-effective as it is not
tailored to specific operation parameters.
