Dynamics of a detuned, optically pumped far-infrared laser

The dynamic behaviour of a coherently pumped single-mode far-infrared ring laser with a homogeneously broadened three-level medium is analysed theoretically, considering detuning between amplifying transition and cavity frequencies. Phase diagrams as a function of cavity detuning and amplitude of the resonant pump field have been obtained, which show different domains of stationary, oscillatory and chaotic output. In some conditions the laser is shown to exhibit hysteresis between different regular self-pulsing regimes, i.e. the phenomenon of generalised bistability.