Coexistence of Spiking and Mixed-mode Oscillations in CO2 Laser with Saturable Absorber

We analyze the dynamics of CO2 laser with a saturable absorber on the base of a model for three- and two-level active and passive media, respectively. This differential model is asymptotically reduced to a discrete one-dimensional map. The fixed point of such a map corresponds to stable periodic spikes and determines their characteristics: period and the energy. In addition, we describe the set of initial conditions which lead to spiking. With initial conditions beyond this set, the system generates mixed-mode oscillations consisting of both small-amplitude oscillations and large-amplitude bursts. Switching between coexisting regimes is discussed