ON THE DISLOCATION DYNAMICS OF PHOTOREFRACTION IN THE NONPOLAR PHASE OF DKDP

Using the dislocation model and approximation of single-mode oscillati ons of mechanical stresses, we analyze for the first time the dislocat ion mechanism behind the excitation of a slowly relaxing component of the high-temperature photorefractive effect in crystals of the KDP gro up. Rayleigh and normal distribution functions are employed in calcula tions for the number of dislocations as a function of the detachment s tress. The results of simulations for the magnitude and the dynamics o f the photoinduced electric field giving rise to photorefraction agree well with the experimental data obtained in earlier studies. Within t he framework of the developed model, the maximum possible density of h olographic data writing in the defect subsystem for crystals of the KD P type is estimated as 10(12) bits/cm(3).