In the present paper we study using the Maxwell-Bloch equations the interaction between a phase conjugated mirror with a thin film of two-level atoms, which in turn are driven by an external coherent field. We find several bifurcation phenomena in the coherent dynamics as well as in the steady-state regime of this system. In particular we find that when the system is in its steady-state regime due to incoherent relaxation, the population inversion of the thin-film atoms may remain constant or even decrease as the external field intensity increases.