INTENSITY DEPENDENT PHOTOREFRACTIVE PROPERTIES OF BATIO3

We have used the light-induced grating erasure technique to measure the photorefractive properties of pure and iron doped BaTiO3. Our experiments were performed using an anisotropic configuration which forbids beam coupling and self-diffraction between the writing beams, resulting in plane parallel intensity fringes that do not change with time. This allowed direct measurement of the charge transport processes without any feedback on the grating due to wave-mixing processes. The results from these experiments show that the photorefractive parameters known as the trap density Npr and the mobility-recombination time product μτr, vary with intensity and are not material constants.