Oscillations in coherent-beam-pumped mutual phase-conjugate emissions

Oscillations are observed in mutual pumped phase conjugate emission when two coherent laser beams are incident on the positive C face of a BaTiO3 crystal in a symmetric configuration. The angle between the laser beams is varied from 30 degrees to 120 degrees. Self-pumped emission and oscillation are also studied with one of the laser beams making angels between 15 degrees and 36 degrees with the crystal. Growth and decay of the mutual pumped phase conjugate signals when either of the laser beams is cut off are also studied. A plausible explanation of the observed features is given in terms of formation and competition between different types of gratings formed in the crystal by the laser beams.