Mode instabilities in a homogeneously broadened ring laser

A nonperturbative theory of a homogeneously broadened ring laser is presented after incorporating spatial hole-burning effects arising due to mutual interference of two counterpropagating cavity modes. It is shown that under suitable conditions the continuous-wave unidirectional lasing mode becomes unstable due to Hopf bifurcations. The time-periodic state associated with these bifurcations corresponds to self-induced pulsations either in one direction or in both directions.