Lateral and focal shifts of phase-conjugated beams in photorefractive materials

It is predicted that when a dc electric field is present or when a probe beam contains temporal frequencies different from that of the pump waves a beam reflected from a photorefractive phase-conjugate mirror will experience lateral and focal shifts. These shifts are a consequence of angular dependence of the phase of the reflectivity and are similar to the Goos-Hänchen effect. The phenomenon becomes more pronounced near resonance.