Threshold and large amplitude self-oscillations in a saturable Rayleigh-gain ring cavity

Periodic instabilities which occur in the output beam of a ring cavity containing a short cell of passive homogeneously broadened two-level atoms are studied as a function of the atomic detuning and the mode spacing in a high-finesse cavity. The output characteristics are found to be very sensitive to the round-trip time of the light through the cavity and to the refractive index. Conditions for the occurrence of large-amplitude self-oscillation are given in terms of these two parameters. >