The dynamics of optically pumped molecular lasers. On its relation with the Lorenz-Haken model

In this paper we review the work on dynamical instabilities in optically pumped molecular lasers (OPLs) that has been carried out during the last 15 years. The main purpose of this review article is to survey and extend the authors' work on optically pumped molecular lasers and to place it in context with other research done in this area, without being a comprehensive review of all previous work done on this topic. In particular, we concentrate on the theoretical interpretation of the Lorenz dynamics observed in the far-infrared ammonia laser by reviewing the results obtained with different models of OPLs. New results corresponding to the dynamics obtained with the Doppler-broadened OPL model are also given. In particular the influence of pump detuning is considered and we also provide a characterization of the chaotic dynamics that definitively clarifies its Lorenz character. Finally a critical account of the present understanding of the far-infrared ammonia laser experiments is given.