Stabilization of the output power of intracavity frequency-doubled   lasers
  Intracavity frequency-doubled solid-state lasers exhibit intensity fluctuations of their light output, which are cause by nonlinear dynamical processes. Up to now, there are different solutions to this problem, but they reduce the output power, increase the size of the laser and/or make them more complicated to assemble. One focus of current research in nonlinear dynamics is derivation of control strategies from mathematical models and their experimental realization. We suggest a method to stabilize the output power by means of an electronic feedback of the emitted infrared light intensity to the pump power. First we show the theoretical predictions of a recently published stability analysis of a rate equation model with feedback. The presented experimental observation show systematic deviations from theory. This makes it necessary to refine the model to explain the deviations. The refinement has direct impact on the improvement of the feedback loop and, therefore, on the application of such a control scheme. 
F. Lange, T. Letz, K. Pyragas, A. Kittel