Bifurcation analysis of a semiconductor laser subject to non-instantaneous phase-conjugate feedback

We consider the question of how the behaviour of a semiconductor laser subject to phase-conjugate feedback depends on the interaction time of the phase-conjugating mirror. We employ continuation techniques to show how the bifurcation diagram in the plane of feedback strength versus pump current changes when the interaction time of the mirror is increased. This shows that for interaction times below 0.1 ns the assumption of instantaneous feedback is justified. On the other hand, increasingly larger interaction times lead to considerable changes in the locking region and a suppression of more complicated dynamics.