Photorefractive mutually-pumped phase conjugation with coherent beams: Sensitivity to small perturbations

Mutually-pumped phase conjugation in BaTiO3 crystal with two coherent incid ent beams has been studied experimentally for the bridge configuration. We observed that when the two pump beams are blocked individually, the transie nt behavior of the phase conjugation reflectivity with coherent beams was g reatly different from that with incoherent beams. The phase conjugate refle ctivity was sensitive to small perturbations such as vibration, exhibiting a change of as much as a factor of 10. The response time to the vibration w as measured to be about 0.3 s.