Optimization of DFWM in Crystals of the Sillenite-Family with Respect to the Polarization of the Signal- and Pump-Waves

Over the last years degenerate four-wave mixing (DPWM) has been demonstrated to be a powerful technique to generate a phase conjugated wave. Among the materials used for DPWM the photorefractive crystals of the sillenite-family belong to the most sensitive ones. On the other hand, the anisotropic properties of these crystals result in a strong dependency of the intensity and the polarization state of the phase conjugated wave on the polarization states of the signal— and pump-waves, on the crystal geometry and thickness and on some other physical parameters.