Speed and diffraction efficiency in feedback-controlled running holograms for photorefractive crystal characterization

We report the measurement of the diffusion length, the Debye screening leng th and the quantum efficiency of photoelectron generation in strongly light absorbing photorefractive Bi12TiO20 crystals, using fringe-locked running hologram experiments. The effective applied electric field inside the sampl e is also computed and self-diffraction is considered. The novelty here, as compared to formerly reported experiments, is that the diffraction efficie ncy is now measured simultaneously with the hologram speed v. From these da ta the above referred to photorefractive and experimental parameters are ob tained without the need for additional experiments. The method is used to a nalyze two photorefractive Bi12TiO20 crystal samples, in different experime ntal conditions, using the 514.5 nm wavelength. The computed parameters are in good agreement with the available information about these samples.