Dynamics of circularly polarized eigenstates in lasers with nonweak atomic coupling

It is shown theoretically and experimentally that the two circularly polarized eigenstates of a laser oscillating on a nonweak atomic coupling transition exhibit two types of vectorial bistability. A rotation and an inhibition mechanism are isolated, depending on the eigenfrequency difference of the two eigenstates. For both mechanisms, the evolution of the hysteresis loop with this frequency difference shows good agreement with a phenomenological Landau's potential model.