Optimization of diffraction efficiency and gain for two-wave mixing in cubic (111)-cut photorefractive piezocrystals

The dependence of the diffraction efficiency of holograms and the effective gain of the signal wave on the polarization and orientation angles is investigated for two-wave mixing in transmission geometry in cubic (1 1 1)-cut photorefractive piezocrystals (classes 23 and 4 3 m). It is shown theoretically that maximum diffraction efficiency and gain in BSO and GaAs depend on the orientation angle. It is confirmed experimentally for BSO crystal (class 23). It is obtained theoretically and experimentally that in 2.1 mm thick BSO crystals the piezoelectric effect leads to an increase of the diffraction efficiency by 70% and of the gain by 30% for certain values of the polarization and orientation angles.