A short introduction to instabilities in optically pumped systems is given. We have put emphasis on homogeneously broadened media. Main results on line competition and stability analyses of single-mode operation are reviewed and compared to experiments. The conditions for Lorenz chaos in cw optically pumped far-infrared (FIR) lasers are formulated. They are more stringent than those derived in two level systems because of the pump laser induced coherence.
M A Dupertuis,
M R Siegrist,
R.R. E Salomaa,
"Line And Mode Competition And Lorenz Chaos In Optically-Pumped Lasers", Proc. SPIE 0667, Optical Chaos, (14 October 1986); doi: 10.1117/12.938840; https://doi.org/10.1117/12.938840