Coherent perfect absorption mediated enhancement and optical bistability   in phase conjugation
  We study phase conjugation in a nonlinear composite slab when the counter propagating pump waves are completely absorbed by means of coherent perfect absorption. Under the undepleted pump approximation the coupling constant and the phase conjugated reflectivity are shown to undergo a substantial increase and multivalued response. The effect can be used for efficient switching of the phase conjugated reflectivity in photonic circuits. 
K. Nireekshan Reddy, Achanta Venu Gopal and S. Dutta Gupta
physics.optics