DYNAMICS OF A CO2 RING LASER WITH A SATURABLE ABSORBER

We present numerical results of the dynamics of a bidirectional single mode (per direction) line tunable CO2 ring laser with an intracavity saturable absorber. We employ a rate equation model which includes las er detuning, Doppler effect of the gain medium caused by gas flowing a nd the coupling of two counter propagating modes. A lower dynamical th reshold was found in such a ring laser system comparing with a Fabry-P erot laser type. In addition to the subcritical Hopf bifurcation and i nverse cascaded period double bifurcation caused by the competition of gain and absorber, we found one more inverse period double bifurcatio n caused by the competition of two counter propagating modes.