Dynamics of operation of a CO2 laser with methanol and ethanol vapours as intracavity saturable absorbers

The results are given of experimental and theoretical investigations of the dynamics of operation of a CO₂ laser with methanol and ethanol vapours as intracavity saturable absorbers. A model of such a laser is proposed. This model accounts for the existence of two longitudinal modes when the frequency is scanned within the limits of the gain profile. The numerical calculations are shown to be in good agreement with the experimentally observed transient processes, including changes between steady-state regular and chaotic lasing when the cavity Q factor is switched.