Optimum thickness of cubic photorefractive piezocrystal for diffraction efficiency

The analytical dependencies of crystal thickness, for which the diffraction efficiency optimized on the polarization angle reaches the maximum values, on the orientation angle are derived. It is shown that optimum thickness of the crystal is inversely proportional to its specific rotation and plots of dependence of crystal optimum thickness on the orientation angle are set of an equidistant curves with period 180 degrees corresponding different local maxima. A distance between these curves is defined by the specific rotation of the crystal or. The optimum thickness for the first local maximum can not be less than pi/(2 \ alpha \). The magnitudes of crystal thickness, optimal for the diffraction efficiency of the hologram and gain coincide for some intervals of the orientation angle theta between the gating vector and direction [001]. Analytical expression, permitting to determine the azimuths of polarization of a reading light, at which the dim-action efficiency will be optimized simultaneously on the polarization angle and crystal thickness, is found.