Bistable phase locking in rocked lasers

We investigate analytically and numerically the dynamics of single mode lasers with periodic ac injection (rocked lasers). Such lasers show phase bistability as the phase of the light emitted by such lasers can lock to either of two values shifted by π. Locking regimes for different lasers are studied showing that the system response is strongly modified in class B lasers due to the influence of relaxation oscillations.